If i has intercourse on 08/15/2013 and got pregnant from it, would my baby be here by now?

Yes: Yes, you are correct, if conception occured 8/15/2013, you would be 43 weeks now. Babies should be delivered before 43 weeks. However, sometimes pregnancy plays tricks on you. I've seen many women who became pregnant a month earlier or later than they thought. Ultrasound in the first trimester is very accurate--sometimes more accurate than a women's memory of periods and conception.