how many weeks would she be today ?

you cant tell unless you know her lmp or her duedate

If she got pregnant from sex on August 3, she would be between 39 weeks and 3 days and 40 weeks and 1 day pregnant. So she should be due basically today. Does that add up to you? Is she due this week?

There is no way to tell how far along someone is by when they had sex since sperm can live inside a body 3-5 days. you would have to list a lmp date or a due date .

lol I'm sorry, but you're wrong. See my comment above. I accounted for the potential conception date gap based on when she could have gotten pregnant from sperm on that date (ranging from THAT day to 5 days later). It's simple math.