I just found out I'm pregnant. I had sex with another guy while me and my boyfriend were split up on February 21st, then had sex with my boyfriend February 27th & the 28th. The one night stand did not get off inside of me, but my boyfriend did. I can't remember when my last period started I just know I was on my period February 11 & 12. Who is most likely the father?
It does not matter if the other guy ejaculated or not. With any sexual contact there is a risk of pregnancy.
Timing wise, it is difficult to predict without knowing when your period started. Going by Feb. 11, you had sex 10 days later with "another". You'd normally be expected to ovulate between days 11-16 of your cycle. We can't determine ovulation after the fact. Sperm can survive up to about 5 days so timing wise "another" can be the father.
Your boyfriend, having sex on days 16-17 of your cycle, may be the father but it is getting late. If you period started by Feb 9, it's unlikely he's the father. The egg is only viable for up to about 48 hours.
You need a DNA test to determine paternity.