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.

[sinbin1]

Thank you for your rapid reply.

Is there such a thing of having a period while pregnant? I know no egg will be shed while pregnant but why do some women bleed just like their period? you seem very educated about all this. I appreciate your help and time.

Also my first ultrasound was done for the nuchal thickness at which the baby measured to be at 13 weeks 1 day. How accurate would you say this is?

[AnnieBrooke]

It is not likely the baby came from the guy before your period.  Sounds like your husband's.

[sinbin1]

Hi, I need some clarification as well. I had sex with a man on 30th of  Oct (unprotected - fully came in me). This was around mid cycle. Then my usual period came on 16th of Nov which assured me that I didnt fall pregnant at that instance. Then things changed with my husband (positively and we got back together) and we had sex a few times on different dates which are 1st of Dec and 8th of Dec (however he pulled out at first time and came inside me on the second date). And around 15-16th of Dec, I felt nauseted and took a pregnancy test and I was pregnant. Since i had that period on 16th of November, I was 100% sure that the baby is from my husband but how likely is it that it also can be from the earlier man? My due date calculated from the ultrasound is 18th of August. Is it a clear cut that my husband is the father or should have my doubts?

I know pulling out is not a safe method of protection for pregnancy but it is a back up method we just use.

[AnnieBrooke]

Hi, Ccoff, if you had sex April 3-8/9 with one guy and sex with the other guy on April 10, and you think you ovulated on the 10th, then there is no way to know which guy is the dad.  The earllier guy's sperm would still be alive in your system when you had sex with the later guy.  

By what method did the doctor tell you the due date, was it from an ultrasound or a little calendar wheel?  How far along in the pregnancy was it?  

[Ccoff1275]

So my Dr told me that my due date is jan1st 2016. I don't have regular periods but they are saying conception was April 10 2015 give our take 5 days. I slept with my ex April 3-8/9ish and reconciled with current bf on the 10. I've read that it's more likely I was pregnant by the ex then by the current the same day as possible ovulation. I'm writing myself to death over this. I have but feeling it is my exes which is what I want. Anyt advice would help me please!!!!!

[AnnieBrooke]

The due date of 1/25 from an early ultrasound adds to the evidence that the sex on May 2 produced the pregnancy.  

Regarding how long to wait to check whether you have miscarried, call your ob-gyn and let him or her advise you.  Some doctors will have you do two hCG blood draws in 48 hours to see if the numbers are increasing or dropping; that is the simplest way to confirm if the pregnancy has faded.  Good luck.