I currently cheated on my bf ....?

I currently cheated on my bf with a guy that I had a past relationship with I lied to my bf and told him I was spending time with my family and instead went to this other guys house. I broke up with the guy I had been with for 8 yrs. and meet this guy thru work after my break up. I wasn't looking for anything serious and neither was he but things didn't work out and we called it quits, then my ex came back into my life and we decided to give it another try but things on his end haven't changed and I ran into the other guy and we started chatting next thing I know I end up at his house I tell him that I am currently back with my ex which of course he doesn't care and we ended up messing around and now I'm not sure how I feel i don't feel guilty because my bf of 8 yrs cheated on me a few yrs ago but I found out because the girl called me i don't want want my bf to find out but now I feel like we are even I know that 2 wrongs don't make a right and to thicken the polt a little more we didn't use protection and I'm not on the pill I know the guy I cheated with has 2 kids so now I'm like crap what if I get pregnant? I don't want to be with the guy I had a fling with he's not bf material should I just not say any thing to anyone unless I become pregnant??