DNA test and potential fathers advice please

[Aaaa3028]

No judgment please, so me and my ex partner split up a while back. I had intercourse with a guy on the 21st of June just the once.

Then me and my ex partner ended up getting back together on the 21st of July and were sleeping together daily since that day. I then had a positive pregnant test on the 5th of August.

My first ultrasound on the 13th of September dated me at 9weeks and 2 days pregnant. Then my most recent ultrasound dated me to be exactly 15 weeks on the 19th of October with a due date of 12/04/2025.

I don’t remember any period dates to go off due to having PCOS, I have a prenatal paternity test booked to find out for definite but just want help working out who is most likely the father? can it still possibly be both even with over 4 weeks difference? Any advice appreciated

The earlier the ultrasound the more accurate it is for dating a pregnancy. By the stage of pregnancy seen on your first ultrasound you would have expected to have had you last period around 9 July (9 weeks and two days before your ultrasound) and got pregnant about 14 days after that around 23 July. So it cannot be the sex you had on 21 June.

Thanks so much. I have always been adamant it could only be from the July but now the paternity test it booked I am panicking there is a chance of having conceived in the June as I hadn’t really considered that being a possibility until now. I know only the DNA will tell for definite but the advice puts me at ease thanks!

The easiest way to work out approximate conception date is to count back 38 weeks from your due date

If you use online calculators based on your due date it gives dates around 21st July as conception dates.

thanks so much for the responses. Yes I’ve been doing all of this online too and have always been sure it could only be in the July but I was just wanting to know if it’s still a possibility to have conceived on the June date or if it’s not possible to be wrong by 4+ weeks with the ultrasounds ect

No I don't think it's possible to be wrong by that many weeks.

Did you go ahead with the prenatal paternity test? How did you get on?
Im in a very similar position right now :(

Your partner is the father I would think.
When they date a pregnancy they date from the (assumed) date of the last period…not from the date you actually got pregnant. There’s about 2 weeks of a difference on average. So dating at 15 weeks pregnant means you probably got pregnant around 13 weeks ago and so on.

Sorry that was a reply to OP. I don’t know your dates @DreamyTiger. I didn’t notice OP had posted a month ago, oops.