I had sex with guy 1 late on 26th June, then had what seemed like a period the next day - it didn't last long. On the 14th of July I went away with another we had unprotected sex. I took the morning after pill on the 16th after we got back. It clearly didn't have an effect because no period followed. After taking a digital pregnancy test, I went to see my doctor On the 20th of August for an ultrasound. He measured the baby at 6 weeks and 1 day. The conception date says 11 June (counting from that last bleed) and the ultrasound. Although there's more than a 14 day difference between the two men, and the conception date reflects before I met the second man but can sperm lurk around in you for long enough for conception to take place that long after a period?