Avatar universal

Should I be worried about who is the father of my baby?

went into the ER May 23rd and they said they saw just a sac, no fetal pole or heartbeat, sac measuring at 5 weeks 1 day- then my 9 week 6 day ultrasound, my baby was measuring 10 weeks 6 days . I had sex with an old friend dating back to that day . So I definitely freaked out a bit . However, he did pull out and I know that for a 100% fact . but conception with him would be considered cycle day 8- as my last period was April 17th. However I ended up hooking up with my ex boyfriend April 28th and he definitely did not pull out . So up until the 9 week ultrasound, that is what I believed to conception. Fast forward, my next couple ultrasounds have been spot on with April 30th as my conception . I had one at 16 weeks, 19 weeks, and 23 weeks, because they did find a tumor in my placenta.

I asked my doctor why the first ultrasound was off and she said 6 days is usually normal and even a MM off will change the size.

The first guy is confident the baby is not his and prenatal DNA are extremely expensive.

I keep reading “early ultrasounds are most accurate” but I’ve also read that up until 20 weeks, most bones and head circumference do hold their accuracy. Would you ladies think that maybe the 9 week ultrasound was just a bit off? When would you use an ultrasound picture to determine if baby has similar feauture like headshape, etc?

to sum it all up, I guess what I’m asking is A. can “precum” really live that long to make it to ovulation? B. Can ultrasound just be off a few days? Only one ultrasound has been off from dates.
3 Responses
Sort by: Helpful Oldest Newest
134578 tn?1614729226
When you say "... my baby was measuring 10 weeks 6 days . I had sex with an old friend dating back to that day," it sounds like you think if a doctor says "Your gestational age is 10 weeks 6 days," that is the same as a doctor telling you that you conceived 10 weeks 6 days ago. Do you think that, or are you aware that is not actually what the doctor is saying?

Gestational age (GA) is the count a doctor or any other medical source will use to count the pregnancy time period in weeks. But the count does not begin on the assumed date of conception. It begins on either the first day of the woman's last period that she had before getting pregnant, or on a computed first day of her last period based on the baby's size as seen in the ultrasound. This is done for historical reasons -- periods are visible, conception is hidden and unknown.

If you had sex 10 weeks 6 days prior to you having an ultrasound in which the doctor gave you a "weeks pregnant" count of 10 weeks 6 days, it doesn't mean you got pregnant from the sex 10 weeks 6 days prior. The time period to pay attention to would be more like 8 weeks 6 days prior.

So, for clarity, let's stop all the talk about "weeks" (because all it does it confuse people) and instead talk about dates.

You had your last period on April 17, right? When you say, " as my last period was April 17th," do you mean the last day of your last period or the first day of your last period?

Then you had sex on what, April 25? with someone.

Then you had sex on April 28 with your ex-boyfriend.

Then on May 23, you had an ultrasound, which didn't show a heartbeat, and now you think might have been a little off. Did they tell you an estimated due date at that time?

Then, you had another ultrasound which you explained in weeks (it was theoretically 9w6d and they told you 10w6d, etc.) What date was that ultrasound, and what estimated due date did they give you at that ultrasound?

Then you had several subsequent ultrasounds, and they presumably either confirmed your estimated due date or changed it, what due date have you most recently been given?
Helpful - 0
No, I know they add 2 weeks because of your period. So what I’m saying is, I should have measured 9 weeks 6 days but I measured 10, which would push conception back a week? However, that was the only ultrasound that would date me a week ahead. At 5 weeks, 16 weeks, 19 weeks, and 23 weeks my estimated due date has all added up to January 22nd. April 17th was the first day of my period. Intercourse with the first guy was April 24th, pulled out. Ex boyfriend was April 28th, did not pull out. However, April 24th was a huge mistake I had not been with my ex for awhile and it basically pushed me right back to him - so after that we did end up back together so even if I did ovulate late, we have been together only since then.
Also, I’ve had an ultrasound every month due to a tumor they found in my placenta.
134578 tn?1614729226
It sounds like you ovulated around May 1. You're asking whether the ultrasound in the ninth or tenth week could be "just a bit off." You said "then my 9 week 6 day ultrasound, my baby was measuring 10 weeks 6 days" and "So what I’m saying is, I should have measured 9 weeks 6 days but I measured 10, which would push conception back a week?" But to try to answer if it's a 'bit off' in relation to known dates such as your period of April 17 and your ovulation possibly May 1, the third piece of information needed is when that ultrasound was (not in weeks, on the calendar) and you haven't said that date.

If there is nothing else in your medical history that puts the suggested conception date into question, and if you had sex on the 24th with Mr. Wrong, then you have the question of the closeness in time between the 24th and the 1st.  

You ask "can 'precum' really live that long to make it to ovulation?" which suggests that you are saying that "pre-***" is somehow lesser than real, manly "***" that might live that long.  

It's not the "pre-***" that gets you pregnant, it is the genuine article, sperm, that rides into your body on the pre-ejaculatory fluid. Pre-ejaculate does not contain sperm when it is produced in the Cowper's gland. But if a guy has ejaculated recently, his urethra will have plenty of sperm in it just hanging around (it's a good, body-temp environment). If the circumstances don't include some time and some peeing, the sperm from an earlier ejaculation can get picked up by the pre-ejaculatory fluid from the erection that happens next, and carry the sperm into the woman's body. One ejaculation produces over a million sperm, there are often plenty left over. If Mr. 24th had had a wet dream or masturbated within a reasonable amount of time of then having sex with you, he could have had lots of perfectly normal, viable sperm ready and waiting, that hitched a ride on the pre-ejaculate.

So the questions then are, how valid is the guess that you ovulated on May 1, and how long could his sperm have lasted in your reproductive tract? The May 1 guess will be valid as long as the ultrasounds have each re-measured the baby and continue to come up with the same due date from fresh calculations each time (rather than merely carrying the old date forward). I would tend to believe the May 1 estimated conception date.

The length of time sperm can last has been reported variously in research. In the doctor's office, some docs will say 3-4 days, but I've never seen that short of a time listed in research, and I tend to think it's older doctors who haven't read the latest stuff who pass that one on.  4-5 or 4-6 days is seen most often in the research. Some even says it's possible for sperm to live 7 days, but other research says sperm are not strong enough to penetrate the egg after 6 days. As you can see, none of this favors Mr. 24th but non of it rules him out absolutely either.

Is the baby a boy or a girl? If a boy, along with the other evidence, I would tend to think Mr. 28th is the dad.
Helpful - 0
The baby is actually a girl! All of the ultrasounds except that one on June 21st which was 6 days ahead. Now everything is measuring on track. Me and Mr. 24th hooked up at night which I’m sure gave him plenty of time to pee, and we didn’t have hook up more than once that day. So now it’s only a matter of if there was sperm in his preejaculate and if it could live from the 24th to the 30th, 1st.
Regarding assuming that if you had sex with someone in the nighttime, they must have cleared their urethra because they had "plenty of time to pee," well ...  unless you were together every single moment the whole day on the 24th, you don't actually know if he didn't have a random "me time" moment that day, guys sometimes do. Probably if he had, he would never tell you or even remember by now.

Anyway, if you had an ultrasound on June 21 that said the pregnancy was at 10 weeks 6 days, your comment that "I had sex with an old friend dating back to that day" doesn't quite line up. A June 21 ultrasound that says 10 weeks 6 days points to April 20 for conception. It could even point to sex before that (due to the long life of sperm), except that you had a period that began on the 17th, meaning you weren't ovulating around the 20th. These two things (not ovulating, and knowing you didn't have sex on April 20), tend to help discount the pinpoint accuracy of the ultrasound you have been questioning.  

Unfortunately, ruling out one ultrasound as not being pinpoint doesn't rule in all the others as being perfect. I can see as a legitimate worry that Mr. 24th might have had errant sperm that got into your system and lasted a while, and there might not be any way for you to know for sure or ask him in a way that he can answer. Sperm wouldn't even have to last until the 1st, if the estimated due date given to you at the other ultrasounds was just rolled forward each time from the first one. You could try asking your doctor about that point, but I would bet they will just do that doctor thing where they say "Oh, there's a margin for error anyway and so we don't change the original date if it only varies slightly."

It seems clear a determination about keeping the baby is not riding on this. (In other words, you're going to keep the baby no matter who the dad is.) If you don't want to do a prenatal DNA test because of the cost, basically the practical thing is to wait until the baby comes, and test with both possible dads. (DNA testing in your case really has to be testing both guys, they are just too close together for certainty.) Testing after the baby is born is about a tenth as costly as doing it before the baby comes.

If you have a serious problem with telling the guy who is now your boyfriend that there is a need to test, (and to pay the big bucks, it would have to be a really serious problem), one of the prenatal testing companies, Ravgen, has something called a "discreet" test they can do with a guy's toothbrush or a swab from his drinking glass. You could test the other guy the normal way. I understand this is a high-cost option, it all depends on how serious the need to know now is.

Your boyfriend has higher odds. It would have helped if the baby was a boy, but even a girl could be from him. It's just not something that can be guaranteed for sure a thousand percent.
Do you think the 9 week ultrasound could be right and at 19/23 weeks genetics has already kicked in and there’s a chance I ovulated and conceived April 24th?
You asked three different things, and the answers are different.
First was "Do you think the 9 week ultrasound could be right?"
If the doctor just let an earlier estimated due date ride, and didn't re-compute from the baby's measurements and developmental markers each time you had an ultrasound, there is a possibility the "9th/10th-week" ultrasound might have been more accurate than your first ultrasound, at which not even a fetal pole was seen. Only when they see something can they give a good measurement.  Whether each ultrasound recalibrated things again is one for your doctor to answer.

Regarding "Do you think that at 19/23 weeks genetics has already kicked in [such that the baby might vary in size from an average measurement]?" Yes indeed, I do think that. Doctors tell women all the time in only their 12th week "give or take 7 days" about ultrasound measurements. The possibility of a margin for error gets larger from there. By the time a woman is in her 40th week, the margin for error is +/- 3 weeks.

You then kind of used as a conclusion to the question about genetics kicking in, "and there's a chance that I ovulated and conceived April 24?" I don't think I have ever said you would have to ovulate or conceive on April 24 to get pregnant by Mr. April 2th. If Mr. April 24 did have sperm, it could have lived in your system until April 29 or April 30, and then met the egg that you ovulated on that day.

All of the above is less likely than you getting pregnant with your regular partner from sex on the 28th. It's just that the guy from the 28th, while in a strong position, can't be absolutely positively guaranteed.
* typo == where it says Mr. April 2th, of course it was supposed to say Mr. April 24th
The only reason I’m asking about ovulation or conception on the 24th is because that ultrasound at 9 weeks, dating about 10. But even then, you mentioned that you don’t believe conception from that day would only date back to April 24th. I just have read that early ultrasounds are the most accurate.
Can we just agree that we don't really know for sure exactly how many weeks and days GA you really were when you had the ultrasound on June 21?  (It would be handier to talk about calendar dates -- did they give you an estimated due date then?) Being 10 weeks 6 days GA seems ruled out by the closeness to your period. But ruling out 10 weeks 6 days doesn't mean the correct answer is necessarily that your pregnancy was in fact at 9 weeks 6 days GA either. (Also, by the 9th week there is already a few days' margin for error when using ultrasounds to try to determine conception.) I don't think you're going to be able to figure this by trying to compute a relationship between the sex on the 24th and the ultrasound on (June) 21st. There are too many variables in the mix, including the margin for error based on varying growth rates of babies. You're either going to have to take the fact that a heartbeat was not heard as of a certain date as the best evidence you have, or you will need to wait for a post-natal DNA test. Unless you do a prenatal DNA test. I'm sorry this is not a cut-and-dried answer. As I've said, your boyfriend has the best odds.
Ugh I hope you are right about the odds! The smallest things have me second seconding it, like the one ultrasound that was off and than at my anatomy scan the humerus was the only part that measured ahead. As far as my ultrasound rolling over, I’m not sure how that works but the way the hospital I go is to set - the measurements are processed as they’re measuring the baby right in front of me so I do believe the baby is right on track. Everything from the femur to BPD has been right on track. We shall see!
Have you been given an estimated due date at every ultrasound?
Yes, I’ve had the same due date - but it not because it rolled over, it because like I said, the tv on the wall show a due date from the femur, to abdoman, and bpd. Luckily it hasn’t been off and at all except of the hemurus.
Also, how did you get the 9 weeks 6 days count that you thought you were supposed to be on June 21, in the first place? Was it from the prior ultrasound's GA? Because it doesn't compute when counted from the first day of your last period.
I’m sorry! I miss calculated the date! It was June 25!
Miscalculated the date of what, the ultrasound? Why did it take calculating, do you have a copy of the ultrasound? Wouldn't it have a date on it?
Yes! The ultrasound does have a date but I didn’t have the ultrasound on me, I just looked back at the calendar and work but it looks like I looked at May instead of June. May 21st is a Monday but so is June 25th. My ultrasound was June 25th.
I wish there was a way I could the pictures to show you!
134578 tn?1614729226
Let's put calendar dates in the slots again.

First day of last period was April 17. (This is for sure, right? Not based on calculations or what you thought when you found out you were 5w1d, but from some independent actual evidence, like you marked a calendar then or went out to buy tampons then and it's on your Visa card, or something. Right?)

Then you had sex on April 24 with the guy you hope is not the dad, who didn't ejaculate.

Then you had sex on April 28, with your ex who is now your boyfriend, who did ejaculate.

Then on May 23, you had an ultrasound, which didn't show a heartbeat. And they told you that you were 5 weeks 1 day GA (from the ultrasound's measurements, right? Not from you telling them when your last period came?)

Then, on June ___ (25th by your calculations) you had an ultrasound in which you were told you were 10 weeks 6 days GA, much to your surprise.

Then you had several more ultrasounds, at 16, 19 and 23 weeks, which "all point to conception on April 30." [Which is different than both your first ultrasound and your second ultrasound. Your first ultrasound would have pointed to May 1, and your second one would have pointed to April 20.] Did each of the later ultrasounds give you the estimated due date of January 22? (If so, they all point to conception on May 1.)
Helpful - 0
Yes mam! I remember April 16 I spotted and April 17th I had full flow. May 23, they did measure 5/1 with no fetal pole or heartbeat. Then 6/25, they told me I was 9/6 but measuring 10/6– then fast word, every other ultrasound has been on point, the only time I’ve measured ahead was my humerus babies humer at 19 weeks. However the doctor told me not worry and most places don’t show every measurement like my doctors office does. So, so far there has been only one ultrasound which hasn’t fit the January 22nd discription. The only reason I am second guessing it, is that 9 week ultrasound and genetics coming into play. I did read that the femur does hold very much accuracy up until 36 weeks.
Also, I did spot once on May 9th and once on May 10th. Took the pregnancy test May 16 after my Flo app had told me I was late two days. First it pushed my period back 2 days, on the third day it changed to being late.
And yes, May 23th the ultrasound measurement measured up to a mean sac diameter of 1.0cm without a fetal pole, which corresponds a date of 5weeks, 1day.
That last (without a fetal pole or heartbeat flutter "corresponds to a date of 5 weeks 1 day") doesn't sound quite like it can be as precise as it says by saying 5 weeks 1 day, to me. A lot of the literature says the baby's heart begins to beat at 22 days after conception (that would be 36 days after the first day of your last period if you are super regular in your cycles), and that would be 5 weeks 1 day. If a heartbeat can be found then, a fetal pole should be visible before then, to my way of thinking. But it isn't enough to upset the applecart over, I'm not an expert and fifth-week ultrasounds are notoriously iffy. Doctors will look at an early 5th week ultrasound and maybe it isn't really 5 weeks yet, maybe there's something else going on, maybe the woman's cycle is super irregular, and all kinds of other things.
and *say* maybe
They estimated 5weeks 1day from how big the gestational sac was measuring, My doctor told me not to worry the fetal pole won’t show til about mid 5th week and heartbeat about 6 weeks. I don’t know what you are trying to get at now? My periods were super regular, 28 days apart.
Just saying that if it were a 6th-week ultrasound you could be more sure than with information from an early fifth week ultrasound, but it is not a big deal. You're doing about the best analysis that can be done with the information you have.
Have an Answer?

You are reading content posted in the DNA / Paternity Community

Top Pregnancy Answerers
13167 tn?1327194124
Austin, TX
4769306 tn?1568490209
Learn About Top Answerers
Didn't find the answer you were looking for?
Ask a question
Popular Resources
Get information and tips on how to help you choose the right place to deliver your baby.
Get the facts on how twins and multiples are formed and your chance of carrying more than one baby at a time.
Learn about the risks and benefits of circumcision.
What to expect during the first hours after delivery.
Learn about early screening and test options for your pregnancy.
Learn about testing and treatment for GBS bacterium.