My boyfriend came in me last night and I came on my period a couple of hours later, is pregnancy possible. I know that any unprotected sex can reslut in pregnancy but, is it realistically possile this close to my cycle?

While not as common, yes it is possible, It is even possible while on your period. So you will have to wait a full month to see if you miss the one next month or not.

Its not very likely. Once you have started your period, the egg has long died off and the endometrial lining has shed making implantation nearly impossible. There are some very unusual cases out there, but most likely you're okay. Testing is the only sure answer though.