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Are ultrasound conception dates accurate?
I discovered I was pregnant unexpectedly, and went to have an ultrasound on May 23rd. Due to having wavering periods, I never really keep track, and therefore I don't know when my last period was. I can give an "estimate" but I really don't know because I never keep track. (Plus I have always been told that because of metabolic issues, and PCOS that it would be very hard for me to get pregnant).
Anyway, not exactly proud of this, but I was with 2 different men in a two week time period. One I didn't use protection with on Saturday April 7th (we have been very good friends for years, and it just happened on a night out drinking/dancing) and the other man I only went out with a few times, and when we slept together the following week (on Saturday April 14th), the condom broke. I didn't think anything of it, because I am almost 38, and this has never happened to me before.
So, my question is, when I went to have my ultrasound, the sonographer did 2 measurements for the conception date: one was 6 weeks and 3 days, and the other one (just to be sure) was 6 weeks 5 days. So, we split the difference and said 6 weeks 4 days. This would make my conception date April 7th, which is the exact night I was with the first man.
Do you think there's a big chance that the 2nd man could potentially be the father? I am hoping the first man is indeed the father, because we have been friends for years, and it would be alot easier to handle. The second man, however, I don't even speak to anymore. I would hate for it to be the second man.
Any advice on people that have gone through this? I guess I just want some confirmation that these ultrasound dates are accurate. The ultrasound tech was amazing, and I feel like she really knew what she was doing, but I just want to make sure that these results couldn't be a whole 7-8 days off.
Anyway, not exactly proud of this, but I was with 2 different men in a two week time period. One I didn't use protection with on Saturday April 7th (we have been very good friends for years, and it just happened on a night out drinking/dancing) and the other man I only went out with a few times, and when we slept together the following week (on Saturday April 14th), the condom broke. I didn't think anything of it, because I am almost 38, and this has never happened to me before.
So, my question is, when I went to have my ultrasound, the sonographer did 2 measurements for the conception date: one was 6 weeks and 3 days, and the other one (just to be sure) was 6 weeks 5 days. So, we split the difference and said 6 weeks 4 days. This would make my conception date April 7th, which is the exact night I was with the first man.
Do you think there's a big chance that the 2nd man could potentially be the father? I am hoping the first man is indeed the father, because we have been friends for years, and it would be alot easier to handle. The second man, however, I don't even speak to anymore. I would hate for it to be the second man.
Any advice on people that have gone through this? I guess I just want some confirmation that these ultrasound dates are accurate. The ultrasound tech was amazing, and I feel like she really knew what she was doing, but I just want to make sure that these results couldn't be a whole 7-8 days off.
Hi annie
I met my girlfriend on the 16 of january while on a world trip. I stayed with her until the 7. of february and we had unprotected intercourse on the 21. of january.
We held a long distance relationship and she told me around the 15.2 that she was pregnant. I returned straight away.
now were both happy with the news and we want the baby to be ours, but she had another boyfriend until we met.
They had intercourse once on the 10.1 and he pulled out.
we visited the doctor on the 2.4 and he sugested the baby was 16weeks2days old. and a due date on the 15 of october.
this would point everything to previous bf beeing the father
her stomach looks so big as well (maybe my mind playing tricks on me)
but she had her period shortly after intercourse with her previous boyfriend.
everything seems to be alright if you look at it logicaly, but the doctor said he was certain but we were wondering if her period was justa implantation bleeding
also i dont know about the chances of her getting pregnant with our first intercourse. it would seem more logical if the conception happened during the 3 weeks we were together the first time
were keeping the baby non the less we just really want this baby to be ours
I met my girlfriend on the 16 of january while on a world trip. I stayed with her until the 7. of february and we had unprotected intercourse on the 21. of january.
We held a long distance relationship and she told me around the 15.2 that she was pregnant. I returned straight away.
now were both happy with the news and we want the baby to be ours, but she had another boyfriend until we met.
They had intercourse once on the 10.1 and he pulled out.
we visited the doctor on the 2.4 and he sugested the baby was 16weeks2days old. and a due date on the 15 of october.
this would point everything to previous bf beeing the father
her stomach looks so big as well (maybe my mind playing tricks on me)
but she had her period shortly after intercourse with her previous boyfriend.
everything seems to be alright if you look at it logicaly, but the doctor said he was certain but we were wondering if her period was justa implantation bleeding
also i dont know about the chances of her getting pregnant with our first intercourse. it would seem more logical if the conception happened during the 3 weeks we were together the first time
were keeping the baby non the less we just really want this baby to be ours
COMMUNITY LEADER
Have you ever done temperature tests or directly tested with an ovulation test kit and found an exact correlation between being "very wet" and your LH surge? Changes in cervical mucus come before ovulation, they don't only happen on the day you ovulate.
I agree that the sex on cycle day 8 is out. You clearly don't ovulate early, and you would have seen a baby on the ultrasound on cycle day 39 if you conceived then.
You're saying it has got to be guy A's baby from sex on May 2, cycle day 18, assuming you ovulated on May 4 or 5, cycle day 20/21, even though you are sometimes irregular. It's not implausible. However, you and guy A have had trouble conceiving even though you have tried, and also, it does seem a little as though if you had conceived on cycle day 20/21, you would have seen something in the ultrasound on cycle day 39.
You had unprotected sexual contact on May 9/10, which you rule out because it was cycle day 25/26 (i.e., too late if being wet was an accurate signal of actual ovulation). Also because your partner did not release, and because you got a positive on cycle day 34 on a home test.
Gotta say, your partner not releasing does not mean that much. Sperm can hang around in the urethra a while and come out with pre-ejacuatory fluid. I suppose by now, he would not be able to tell you if he had had an ejaculation in the hours before you and he had sex? (Guys are not prone to want to volunteer that they a) had sex or b) masturbated before their date with the now-pregnant woman even if they could remember, which they usually can't.) You also can't rule out the sex with guy B as producing the pregnancy based on a home test picking up a pregnancy nine days later. It really depends on how concentrated your urine was, or how dehydrated you were. Tests these days are pretty sensitive. Just based on the information you have now, I would not rule out the sex on May 9/10 quite yet.
Can you do your next ultrasound the week after next at the latest? I would tell them you are irregular and seem to ovulate late anyway, so you want them to base the estimated-due-date calculation on the size and developmental markers of the baby only, not on the first day of your lmp. Then take home the estimated due date and put it into a conception calculator.
Write back when you get your next ultrasound. They should be able to give you much more precise information then.
I agree that the sex on cycle day 8 is out. You clearly don't ovulate early, and you would have seen a baby on the ultrasound on cycle day 39 if you conceived then.
You're saying it has got to be guy A's baby from sex on May 2, cycle day 18, assuming you ovulated on May 4 or 5, cycle day 20/21, even though you are sometimes irregular. It's not implausible. However, you and guy A have had trouble conceiving even though you have tried, and also, it does seem a little as though if you had conceived on cycle day 20/21, you would have seen something in the ultrasound on cycle day 39.
You had unprotected sexual contact on May 9/10, which you rule out because it was cycle day 25/26 (i.e., too late if being wet was an accurate signal of actual ovulation). Also because your partner did not release, and because you got a positive on cycle day 34 on a home test.
Gotta say, your partner not releasing does not mean that much. Sperm can hang around in the urethra a while and come out with pre-ejacuatory fluid. I suppose by now, he would not be able to tell you if he had had an ejaculation in the hours before you and he had sex? (Guys are not prone to want to volunteer that they a) had sex or b) masturbated before their date with the now-pregnant woman even if they could remember, which they usually can't.) You also can't rule out the sex with guy B as producing the pregnancy based on a home test picking up a pregnancy nine days later. It really depends on how concentrated your urine was, or how dehydrated you were. Tests these days are pretty sensitive. Just based on the information you have now, I would not rule out the sex on May 9/10 quite yet.
Can you do your next ultrasound the week after next at the latest? I would tell them you are irregular and seem to ovulate late anyway, so you want them to base the estimated-due-date calculation on the size and developmental markers of the baby only, not on the first day of your lmp. Then take home the estimated due date and put it into a conception calculator.
Write back when you get your next ultrasound. They should be able to give you much more precise information then.
Hi Annie,
So, this is my situation. I have 35-days cycle period, but im not too regular. My post-ovulation period has always been between 14-15 days; meaning that I ovulate not earlier than 18cd to 24cd. I was trying to conceive with my partner (GUY A) for years but he was diagnosed with low sperm count, so we were having infertility problems. Because of that, I am tracking my body every month, I am not using any contraceptive method, and taking fertility vits. This month was crazy because we were having a lot of issues with guy A, and I ended up by having sporadic affairs with my ex boyfriend (guy B). So those are the events:
April 15 (cd1). First day of my period
April 22 (cd8). Sex with B, quick penetration, he did not finish at all.
May 2 (cd18). Sex with A, he finished inside.
May 4-5 (cd 20-21). I was very wet, which is my symptom of ovulation
May 9-10 (cd 25-26). Sex with B, withdrawal method, again the penetration only lasted few seconds!
May 18 (cd 34) I found out I was pregnant on a HPT, the line popped out almost inmediatly (high HCG?).
May 22 (cd 38) Blood test positive.
May 23 (cd 39) The ultrasound found NO gestational sac yet. They said it may be too early. (what does it mean?)
I have to take another sono. I think the dad is A (I HOPE!), but I need reassurance otherwise I will get crazy. I don't want to carry a baby of my ex at all.
- I ruled out conception on the cd8, because in that case I think the sono would have detected a sac!
- I ruled out conception on the 25 or 26 coz I don't think the HTP would detect such strong and quick line only 9days after conception. Besides, even for me it sounds like a very late ovulation.
Does it make sense or am I delusional? some help please ! :(
So, this is my situation. I have 35-days cycle period, but im not too regular. My post-ovulation period has always been between 14-15 days; meaning that I ovulate not earlier than 18cd to 24cd. I was trying to conceive with my partner (GUY A) for years but he was diagnosed with low sperm count, so we were having infertility problems. Because of that, I am tracking my body every month, I am not using any contraceptive method, and taking fertility vits. This month was crazy because we were having a lot of issues with guy A, and I ended up by having sporadic affairs with my ex boyfriend (guy B). So those are the events:
April 15 (cd1). First day of my period
April 22 (cd8). Sex with B, quick penetration, he did not finish at all.
May 2 (cd18). Sex with A, he finished inside.
May 4-5 (cd 20-21). I was very wet, which is my symptom of ovulation
May 9-10 (cd 25-26). Sex with B, withdrawal method, again the penetration only lasted few seconds!
May 18 (cd 34) I found out I was pregnant on a HPT, the line popped out almost inmediatly (high HCG?).
May 22 (cd 38) Blood test positive.
May 23 (cd 39) The ultrasound found NO gestational sac yet. They said it may be too early. (what does it mean?)
I have to take another sono. I think the dad is A (I HOPE!), but I need reassurance otherwise I will get crazy. I don't want to carry a baby of my ex at all.
- I ruled out conception on the cd8, because in that case I think the sono would have detected a sac!
- I ruled out conception on the 25 or 26 coz I don't think the HTP would detect such strong and quick line only 9days after conception. Besides, even for me it sounds like a very late ovulation.
Does it make sense or am I delusional? some help please ! :(
Did you ever get assurance from the 7 week scan? My dates and situation are very similar to yours. DD of Dec 3 based on Ultra Sound at 6 week 5 day. LMP (which wasn't really regular, and only spotted one day) put my due date at 11/27. Breakups, hoopups etc Im extremely stressed about my situation. If DD is correct and Conception is 3-7 and on Im in the clear!
COMMUNITY LEADER
One thing that definitely works differently in Britain is the use of the month, day and year in numbers. In the U.S., we use a month, day, year format, so for example, May 1 would be written 5-1-2015 (or 05-01-2015). I hope I get the translations right. If you want to be sure I understand you completely, write out the month so I won't mistake January 5 for May 1. lol
I assume you are saying, you were told on April 13 that you were 11 weeks and 1 day pregnant, from information gleaned from the ultrasound scan of the embryo. You're wondering if that means you got pregnant 11 weeks 1 day ago, or if that count begins on the (assumed) first day of your last period and not on the estimated ovulation date.
When a doctor, nurse, utrasound technician, or even medical textbook says x weeks x days "pregnant," they use the traditional medical way of counting out pregnancy, which begins on the first day of the woman's last period that she had before getting pregnant. This is because historically that is the only big signal a doctor had to go on, not because anyone thinks you were pregnant on the first day of your period. Ultrasounds have only come widely into use relatively recently as far as obstetrics is concerned. Before that, the only thing a doc could do was ask a woman when she had her last period, and begin the clock there.
This form of counting, confusing as it is for everyone, is how pregnancies are timed even today. Two weeks after the period, the assumption goes, the woman would ovulate. Obviously a lot of women are not on the dot with the two-week interval, but that is the traditional counting method (called the GA or gestational age). If an ultrasound were to see a baby and identify it as a certain size, and the woman's cycles were irregular and she hadn't had a period in a long time, the ultrasound would just measure the embryo and say the baby was consistent in size with a baby whose mom's first day of her last period was on a certain date, two weeks before ovulation.
If you were told on April 13 that your GA was 11 weeks and 1 day, that was like being told that the ultrasound suggests you got pregnant 9 weeks and 1 day ago. (Did they give you an estimated due date? It is easier to understand and compute these things from the e.d.d. than from weeks and days.)
Anyway, 9 weeks 1 day back from April 13 suggests you conceived around February 8. The margin for error when using an eleventh-week ultrasound to try to determine conception is about +/- 6 days, in other words, the dating could be spot-on or it could be that divergent, due to the different growth rates of embryos. So, your range for getting pregnant from this would be around February 2 through 14, and let's not forget that (if the sex was unprotected), you could have had sex with someone as early as January 26 or 27 and the sperm could (theoretically) still be alive in your system and viable from that sex and get you pregnant on February 2.
That doesn't stretch back to January 21. It does (tentatively) rule in the second guy as a possibility (I am assuming that where you wrote "24-25.04.15" you meant January 24-25 and not April 24-25). It also rules in the guy on February 5. That is especially true if the sex was unprotected.
Did you have sex with anyone after February 5? Is the baby a girl?
I assume you are saying, you were told on April 13 that you were 11 weeks and 1 day pregnant, from information gleaned from the ultrasound scan of the embryo. You're wondering if that means you got pregnant 11 weeks 1 day ago, or if that count begins on the (assumed) first day of your last period and not on the estimated ovulation date.
When a doctor, nurse, utrasound technician, or even medical textbook says x weeks x days "pregnant," they use the traditional medical way of counting out pregnancy, which begins on the first day of the woman's last period that she had before getting pregnant. This is because historically that is the only big signal a doctor had to go on, not because anyone thinks you were pregnant on the first day of your period. Ultrasounds have only come widely into use relatively recently as far as obstetrics is concerned. Before that, the only thing a doc could do was ask a woman when she had her last period, and begin the clock there.
This form of counting, confusing as it is for everyone, is how pregnancies are timed even today. Two weeks after the period, the assumption goes, the woman would ovulate. Obviously a lot of women are not on the dot with the two-week interval, but that is the traditional counting method (called the GA or gestational age). If an ultrasound were to see a baby and identify it as a certain size, and the woman's cycles were irregular and she hadn't had a period in a long time, the ultrasound would just measure the embryo and say the baby was consistent in size with a baby whose mom's first day of her last period was on a certain date, two weeks before ovulation.
If you were told on April 13 that your GA was 11 weeks and 1 day, that was like being told that the ultrasound suggests you got pregnant 9 weeks and 1 day ago. (Did they give you an estimated due date? It is easier to understand and compute these things from the e.d.d. than from weeks and days.)
Anyway, 9 weeks 1 day back from April 13 suggests you conceived around February 8. The margin for error when using an eleventh-week ultrasound to try to determine conception is about +/- 6 days, in other words, the dating could be spot-on or it could be that divergent, due to the different growth rates of embryos. So, your range for getting pregnant from this would be around February 2 through 14, and let's not forget that (if the sex was unprotected), you could have had sex with someone as early as January 26 or 27 and the sperm could (theoretically) still be alive in your system and viable from that sex and get you pregnant on February 2.
That doesn't stretch back to January 21. It does (tentatively) rule in the second guy as a possibility (I am assuming that where you wrote "24-25.04.15" you meant January 24-25 and not April 24-25). It also rules in the guy on February 5. That is especially true if the sex was unprotected.
Did you have sex with anyone after February 5? Is the baby a girl?
Hi Annie,
I really need clarification. I've been working out my dates on the basis of the dating scan telling me i was 11wk1d pregnant on the 13.04.15 which I thought meant i conceived on 25.01.15. However reading this thread I'm now confused as to how the conception dates work. I'm not aware of the date of my lmp and I've had periods every month during the pregnancy resulting in me just finding out about my pregnant. The problem is i was with guy A on 21.01.15 and guy B on the 24-25.04.15 and then guy A on the 05.02.15. I thought counting back 11wks1d and landing on the 24th meant that it was Guy B's probably. However reading the above posts seems to suggest that its more than likely to be guy B correct? Or do our dating scans work differently in the UK?
Thank you for your help.
I really need clarification. I've been working out my dates on the basis of the dating scan telling me i was 11wk1d pregnant on the 13.04.15 which I thought meant i conceived on 25.01.15. However reading this thread I'm now confused as to how the conception dates work. I'm not aware of the date of my lmp and I've had periods every month during the pregnancy resulting in me just finding out about my pregnant. The problem is i was with guy A on 21.01.15 and guy B on the 24-25.04.15 and then guy A on the 05.02.15. I thought counting back 11wks1d and landing on the 24th meant that it was Guy B's probably. However reading the above posts seems to suggest that its more than likely to be guy B correct? Or do our dating scans work differently in the UK?
Thank you for your help.
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