I had a one-night stand. There was no penetration but my partner ejaculated on my vagina. The following morning, early, I started my period. It was heavy just like always. Following, I had sex with another partner(who ended up becoming my boyfriend) maybe a week later, totally unprotected with penetration. I did not have a period after that and found out a month later that I was pregnant. A bit complicated but, question is, Who is more likely to have gotten me pregnant? The one night guy or the other guy? Could I have already been pregnant before sleeping with my soon to be boyfriend and having a missed period? I am single and am having paternity doubts raised by my family.