Am I the only one to question the way they calculate pregnancies and how far along you are when you first find out?

As you can see here the last time I had sex was on the 11th and it was conveniently on ovulation day and then I had tested positive through seven pregnancy tests the day before my period was supposed to come I am three days past my period and have not had it but if we go into technicalities I should not be what it’s claiming below

I did not have sex before during or after my period until 11 August one day that just so happen to be ovulation day we got lucky Wham! Bam it was a done deal however I don’t agree that I should be four weeks and two days even though that’s pretty much an estimate it should be more taken in consideration when the last time you had sex when was your ovulation date if they know it it’s just aggravating I don’t know why it’s bugging me so much today but it is it’s really bugging me today and I’m not sure if I’m only one that’s ever had this issue I’m still in disbelief that I’m pregnant I would like to see an ultrasound to prove that I’m pregnant because I don’t really believe it. maybe it’s just because I’m so much in disbelief that I’m working myself up over nothing but however it just drives me crazy I’m not four weeks pregnant there’s no way I’m four weeks pregnant you can’t like go back in time and do it’s thing. I’m making myself crazy I’m sorry guys 😭