When did I fall pregnant?

[Strawberryfruits]

I had sexual intercourse with A on the 29th January (with a condom, I’m just overthinking, I think I just need peace of mind) and I had sexual intercouse with B many times without a condom.

On the 4th of April, I had a scan that shows I was 8 weeks and 3 days pregnant and my due date is the 11th November.

I also took a clear blue test on the 3rd of March that stated I was 2-3 weeks pregnant

When would I needed to have sexual intercourse for pregnancy to happen?

Basically this post is for peace of mind.

It seems incredibly unlikely it could be A's baby. Counting 8 weeks 3 days back, likely you ovulated mid-February which is when you would have got pregnant, unless you have very long/short cycles.

My cycles have been so irregular as I come off the pill and my periods were shorts sometimes. I think I did have a small bleed just after my intercourse with A but maybe only for 3 days

Could my midwife be incorrect with the gestational age?

Going purely off dates, you're looking at a conception around Mid Feb.

Very unlikely to be wrong if you've had a scan, as they would have used the measurements to calculate. Sometimes dates get moved at the 12 week scan but only by a few days.

As pp, mid Feb is when conception was likely to have happened.

At 8 weeks, it’s very unlikely that the midwife would have got the dates wrong by a full 2+ weeks

Yes that's what I was thinking. I have another scan in 2 weeks will get a definite answer then. With A I also used a condom but he is saying he wants a DNA test and he's making me worry.

The scan could be out a bit at this stage but very unlikely to be out by much if your pregnancy is growing normally.

There's no way it is chap A. The date given to you by the scanner will have assumed you conceived 6 weeks 3 days before your scan, and that would mean conception on or around 19 Feb. No sperm lives for that long.

This. I had a threatened miscarriage so I had a lot of scans between 6 and 12 weeks. During that time the baby goes from blob to kidney bean to kidney bean with a heart beat to vaguely baby shaped to baby with arms and legs.