working out when I conceived (detailed)

[Anonyymmmmm]

So I am due on the 19 June 2026,
and I got into a new relationship.
my last period was 12th September and lasted 4/5 days. I did the deed on the 17th the day after I came off was on around day 5/6 of my cycle.
I then got into a new relationship with someone who I had already been sexually active with around the same time and was sexually active pretty much every day after that going forward, now that we are in a relationship.
I missed my period the next month which was due on the 10th or 11th I have on average a 29/30 day cycle.
I tested positive on the 16th of October.
I did a scan straight away
• 5w 1d (private) 20th October
and another in hospital on
12th November
• 8w 1/2d
these are the gestational ages of the scans so fetal age is - 2 weeks of that so saying I conceived around end of September 2 weeks after my LMP.
would this be correct?
when would I have likely conceived?

According to Google you most likely conceived between 24th and 28th September but it's possible anywhere from 18th September to 3rd October. If there was an overlap, a DNA test is the only way to know for sure who the father is.

Looking at your due date and cycle length you likely conceived in the second half of September or early October I think. But it's more likely end of September into early October assuming your ovulation happened around your usual time, do you know this?

I'm inclined to agree with the above putting conception in late Sept/early October. I found out I am pregnant on 12th October and by my LMP I'd be due on 27th June. That was with ovulation in the first weekend of October