When did I get pregnant

[F12GH]

My due date is on the 20th March. When did I get pregnant

Last week of June? Depending on cycle length?

Years ago my due date was 14th March. I got pregnant around end of June. I think I tested positive 14th July and it said 2-3 weeks

me and my boyfriend were separated the last two weeks of June so that’s why I’m thinking my due date must be wrong

Due dates can be wrong, sperm can also live inside the body for several days.

Did you have sex with anyone else in that period of time?

No

In theory your last period was mid June and you conceived in the weeks after that. But it varies with how long your cycle is, sperm can remain inside the womb for several days etc.

Are you worried baby will come on a different day or is he questioning who the father is?

40 weeks back from 14th March is about the 14th June. If you have a regular cycle, you would've ovulated end of June, maybe around the 28th, but having sex anytime from 6 days before to 2 days after that would equal a pregnancy with that due date. If your cycle is longer/you ovulated a bit later then it could easily have resulted from sex in early July.

My last period was end of may and I have a regular cycle that’s why I’m confused

My last period was end of may that’s why I’m confused

If it helps my official date of conception was definitely 10 days out as my husband and I were on opposite sides of the world. I never figured out whether it was early or late.

Average pregnancy is 38-42 weeks, so it looks like they've taken your dates and gone with 42 weeks rather than 40.

They have never asked me when my last period was

You have posted this same question 2 times with pretty much similar scenarios. No one will be able to tell you who the father is for sure. You are better off waiting until you can test and find out.

Op has said they didn't sleep with anyone else?

This looks like the same person...