Are ultrasound conception dates accurate?

[tina6146]

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.

[PattySuarez2]

Good morning Annie,

Unfortunately I am bleeding heavier and heavier every day, but not cramps or clots. The blood looks fresher too. It has been a terrible and stressful time but my partner has been so supportive and lovely, that ironically this has helped us as couple. I like to think that things happen for a reason.

I read that once you start bleeding heavily there is nothing you can do. :( But how long I have to wait to check if I actually miscarried. and , do I take a pregnancy test? another ultrasound?

And about dates, can I safely say that my partner is the dad? How accurately these dates can be?

Thank you for your advises!

[AnnieBrooke]

From the due date of 1/25, my calculator also gets the conception date of May 4.  It adds more to the evidence that the sex on May 2 produced the pregnancy.  (Sperm can easily live from May 2 to May 4 in your reproductive tract.)  

If you are having bleeding, the best thing is to stay off your feet until the bleeding has stopped for 24 hours, and stay hydrated.   Alternately, if you are near your doctor's clinic, you might ask about having a blood draw every couple of days to see if your hCG levels are going up at the appropriate rate.  There is nothing you or a doctor can do to stop a miscarriage at this stage, it is all up to the embryo and if it is developing or fading.  But if you merely have a broken blood vessel or something else like that, staying at rest can calm uterine contractions, and that can help stop bleeding.  I'm sorry this is happening.

Good luck to you.

[PattySuarez2]

Due date (LPM): 01/20/2016
Due date (Ultrasound): 01/25/2016

Due dates were given by the doctor, I don't understand how it works!

[PattySuarez2]

Hi Annie, yes I did the ultrasound today, Sunday. The tech did the assessment based on the measurements. The medical report states: Menstrual age of 5 weeks 6 days. I did the ovulation date estimate here http://www.babymed.com/pregnancy-due-date-calculator?redirect=1 using the 5w6d.

Due date (LPM): 01/20/2016
Due date (Ultrasound): 01/25/2016

[AnnieBrooke]

You say you had the ultrasound today?  (I.e., on a Sunday?  Was it at your regular doctor's or at an ER?)

Did the doctor give you an estimated due date?  You said "This put my ovulation day on May 4."  Did you do the calculation or did the doctor say "You are due on ____ (date)" and then you asked him or her when you might have ovulated?

Sometimes it is a lot easier for me to be helpful if I know how much was verbatim from the doctor or tech, and how much was analysis and extrapolation by the poster from what the doctor said.

[PattySuarez2]

HI Annie!

I did another ultrasound today, we did see gestational sac, yolk sac and embryo. No heart beat tho. The doctor put me at 5 weeks 6 days, according to the measurements, which are:

Gestational sac 11.3 mm
Yolk sac: 2.4 mm
Embryo: 6 mm

This put my "ovulation" day on May04. Did I get pregnant on May02 or May09? How accurate is this?

The doctor also put me as risk of miscarriage, because I am spotting dark blood since 6 days :(

Thanks!