Does Vaginal Bleeding After Having Sex Cause Pregnancy?

I was fooling around in bed with my boyfriend, and we got serious and we tried to make love..It would have been my first time but, when he tried to push his penis into my vagina he couldn't do it..So he claims that I didn't lose my virginity, although there were drops of blood on his t-shirt and on my underwear..So when he ejaculated he moved away from me, but I had a few drops on my ties is it possible that I have lose my virginity ? And that there is a chance I'm pregnant ?
I'm only 17 pls HELP !