I am currently 25 week's pregnant and my EDD(given by vaginal ultrasound) is 1/20/2012. I was told that I must have conceived either the last week in April or the first week in May. I had sex in march and on April 2nd and not again until after 5/14/11. My last period I can recall started on 3/18/11 and they are usually only about 3 day's or so long if I even have one. My question: is it more likely that I got pregnant in April or May? Is there any way that I could have conceived from my encounter in May? Please... any help is appreciated!