Due date confusion...

😆

Hi all, I’m really curious as to what my due date is going to be, but my appointment isn’t for another few weeks. I’ve tried a few different sites and I’m getting different dates for each site. I tried counting 40 weeks from my last period. Then someone said to do that, but minus three days. I know the doctor will have the “correct” one, I’m just curious to find out what it might be. Anyone have a tried and true method that is willing to share? :)