I was really drunk on a night out and i think a guy cummed on my hand, i then later when to the toilet and thinking that he had washed my hand and used a different one to wipe myself, i was on the second day of my period at the time and was wearing a tampon. This was back in November and the period i had in December was normal and early as usual but when my period was finished i had lower back pain, i don't normally get this and my boobs appear bigger and firmer aswell. Is there any chance that i could be pregnant ?