Any ideas?

My period is 3 days late...but I saw my boyfriend a couple of weeks ago and that was supposed to be my fertile week but I was sick the week before so I don’t know if that had any effect or not, anyway when I saw him I gave him a blow job and afterwards he ate me out and sorta fingered me but not really, I don’t think he had anything on his fingers and he said he didn’t, I don’t know if there’s anyway his semen could’ve gotten on the shirt I was wearing and got near that area afterwards. Is there any possible way I could get pregnant. Couple of weeks ago I had cramping and some headaches (which could’ve been from stress) but other than that I have had no symptoms of my period coming or anything. I have irregular periods. I took a test because I’m just a paranoid person and it was negative.