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Coception date and ultrasound accuracy?
I've done a lot of research myself but would like some other opinions on this matter as well. I am 18 weeks today. My due date my OB gave me from a dating ultrasound was Feb 5th- this ultrasound was taken at 7 weeks. About a week later at 8 weeks I ended up going to the ER because I was bleeding a little so I of course wanted to make sure everything was okay. The doctors there also performed all sorts of ultrasounds and the dating scan suggested I was 1 day further than my first ultrasound, putting my due date at Feb 4th! . Based on my period I would of ovulated around the 10th but my two dating scans due dates suggests I conceived on either the 14th or the 15th of May. I need help and some insight in determining when I conceived. The first day of my last period was either April 26th or 27th (one of the two for sure) I had sex with Guy A. on May 3rd - (not sure if this matters or not but it was in the very early morning of May 3rd, I came over May 2nd but sex was around 3AM so technically fell on May 3rd. Anyway, this guy was pretty drunk and could barely keep it up and ended up giving up before he could even ejaculate. So NO ejaculation took place with Guy A. I then had sex with Guy B May 5th which this time this guy did ejaculate inside of me and then had sex with Guy B another time on May 12th and he came inside of me this time also. I have a little more info that may be helpful- I took a home pregnancy test on May 20th which came back negative(I took this test because my breasts were sore, wasn't sure if it was from pregnancy or my period getting ready to start) I then had a little bleeding on May 22nd so I thought it was my period but the next day there was nothing so I took a blood test at my doctors and it came back positive for pregnancy. On May 30th My hcg levels were at 390 and the doctor was a bit concerned because although my levels suggested I was pregnant there was not a sac in my uterus at this time. Please no harsh comments, I'm just trying to give myself a little peace of mind while finishing out this pregnancy. I'd rather be as stress free for this sweet innocent child. ( also, I have gotten checked and came back clean for any STDs ) so that's a plus! Anyway, please help!!!!
COMMUNITY LEADER
Ultrasounds per se aren't 5 days off, possibly the person who told you that was talking about a ninth- or tenth-week ultrasound. Using an ultrasound to date conception varies in precision based on when (how early or late) they are in the pregnancy. By your 40th week, an ultrasound can give you a date that is three weeks off! All embryos begin as one cell, and then divide to two, and then to four, and so on at a known rate for a while, but after about week 7 or 8 some babies might be growing a little faster and some might be growing a little slower. By week 12 (counted from the first day of your last period) the margin for error doctors will often use is +/- 7 days. But your ultrasounds were early. Their margin for error might be +/- 1 day or possibly +/- 2 days. Not enough to make a difference here.
2 Comments
Thanks again
I just had an another ultrasound done to reveal my baby's gender :) I'm still measuring right on track for the due date of Feb 5th. Is it safe to say I did not conceieve any sooner than May 14th since all of the ultrasounds correspond with each other?
COMMUNITY LEADER
That means the information from the early ultrasounds is fine to use to make the assessment, and they indicate conception no earlier than the 14th of May. Though it sounds like the guy on May 3 was in no condition to remember (by the time you found out you were pregnant or even probably by the next day) if he had recently ejaculated before your encounter, it doesn't matter anyway. Even if some of his sperm had gotten into your system, it wouldn't have still been alive by May 14.
2 Comments
Thank you so much for ur input. Maybe I can get some sleep tonight
One more question for you! The ultrasounds dating goes 5 +/- either way correct? If so would that still mean Guy A was too early right?
COMMUNITY LEADER
I already thought you should rule out the guy on May 3rd; that your ultrasounds are consistent doesn't change this.
2 Comments
Yes I just wanted to triple make sure! Im an over thinker.
In short, don't worry.
COMMUNITY LEADER
It would seem like Guy A was too early from what you have said. Your estimated due dates given to you by ultrasound don't suggest sex May 3 got you pregnant.
When talking about your early ultrasounds, you say "at 7 weeks" and "about a week later at 8 weeks." This is less specific than ultrasound techs or doctors usually are when talking about weeks pregnant; I was trying to see how it corresponded with the calendar dates, but you don't note those. Did the doctor, looking at an ultrasound, give a specific number of weeks and days, such as 7 weeks 0 days or 8 weeks 1 day? This won't change the interpretation much, but it would be helpful to know what the doctor said in weeks and days, and on what day. Was your first ultrasound on June 19? (That would be "at 7 weeks" if today you are at 18 weeks 0 days.)
If the ultrasound dates are a long way off June 19 and 26, or if the doctors said something other than 7 weeks 0 days and 8 weeks 0 days, write back. Unless they gave wildly different estimates than that on very different days than those, it's hard to see how Guy A would be in the right time window to get you pregnant. I'd do the DNA test just to never have to wonder, but I would not stew over this all through the pregnancy, It seems Guy A is too early.
When talking about your early ultrasounds, you say "at 7 weeks" and "about a week later at 8 weeks." This is less specific than ultrasound techs or doctors usually are when talking about weeks pregnant; I was trying to see how it corresponded with the calendar dates, but you don't note those. Did the doctor, looking at an ultrasound, give a specific number of weeks and days, such as 7 weeks 0 days or 8 weeks 1 day? This won't change the interpretation much, but it would be helpful to know what the doctor said in weeks and days, and on what day. Was your first ultrasound on June 19? (That would be "at 7 weeks" if today you are at 18 weeks 0 days.)
If the ultrasound dates are a long way off June 19 and 26, or if the doctors said something other than 7 weeks 0 days and 8 weeks 0 days, write back. Unless they gave wildly different estimates than that on very different days than those, it's hard to see how Guy A would be in the right time window to get you pregnant. I'd do the DNA test just to never have to wonder, but I would not stew over this all through the pregnancy, It seems Guy A is too early.
2 Comments
I'm sorry for not being specific but I can provide you with that info! On June 20th the ultrasound date measured me at 7 weeks 1 day and on June 29th my ultrasound date measured me at 8 weeks 4 days
And today based off of my first ultrasound I am 18 weeks 0 days
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