My last period was on 23/09/2018 and they say i'm 7 weeks and 6 days pregnant so when did i conceive?

Pregnancy: Hi, You can only get pregnant during ovulation, meaning the time when the egg is released from the ovary. There is a lot of variation between women but if your menstrual cycles are very regular, and the first day of your period was 23/09/2018, likely you conceived about 11-14 days afterwards, possibly up to 20 days after. So somewhere between 03/10/2018 - 10/10/2018, give or take a few days.