On Sunday 2/15/2015 my boyfriend and I went a little too far and he was rubbing his penis while I was hovering over him wearing loose underwear (not sitting on him). My vagina was not in direct contact with his penis and there was never any penetration. The moment before he orgasmed/ ejaculated he remembers immediately covering his penis with his underwear, hand and shorts. I do not recall feeling any semen land anywhere on my body. I just remember feeling a cold sensation, possibly cold air where my inner thigh meets my labia.
Since this was the furthest my boyfriend and I had ever gone sexually,I got scared that some semen could have possibly reached me before he covered himself and I began to doubt if that cold sensation I felt on my inner thigh was really just air. My boyfriend assured me that semen should feel warm or at least body temperature and we checked my underwear and it was completely dry.
I took Plan B One Step 20 hours after the incident (took it on Monday2/16). My period is usually regular but can be a week late due to stress which I was the week before the incident. I was expecting my period on Tuesday 2/17 and it still hasn't come. I took a home pregnancy test this morning and it was negative.
Can Plan B delay a period for this long? What are my chances of being pregnant? I know I might be overthinking but I'm still really worried and scared and any help would be greatly appreciated.