My boyfriend and I were dry humping last night with our underwear on (and I had a day pad/pantiliner on). I also want to note that I do not take birth control because I'm not sexually active. Though my bf pulled far away from me long before ejaculating, we do not know if precum was present. I did not know what happened until he told me about the incident as we were walking to his car (about a 15 min walk) so I was unable to check automatically if there was anything on my underwear. When I got back I found a semi-dry spot on my underwear beside where the pad is but because of its positioning I think it was just from me as the acidity of my vagina is pretty insane and that has gotten on my underwear countless times before anyway (this has ben a thing since long before I even had a boyfriend). After it occurred I showered and tried to relax. I've done some research and it seems that because there were two layers, he doesn't know if the precum existed anyway/when it happened if it did, and on top of that it would've had to actually get into my vagina, etc. that it's super unlikely but I'm still scared and not sure if I'm just being extremely irrational. Does anyone here think I need to take an emergency contraceptive? I'm a 19 y/o college student who has never made this mistake before and I'm terrified beyond belief, I have had trouble sleeping since then because the fear of what I do not know is eating at me. I also just ended my period a couple of days ago so I won't know for sure until mid/late December, assuming that my period isn't being irregular (as it often is).