Am I pregnant?

Ok so first of there was a night at the beginning of this month that me and my boyfriend was having sex unprotected and I'm not 100% he didn't cum in me. Well later that night I was having really bad pains and I went to the bathroom n seen some blood now mind u I had already had my period for the month. So was just wondering what that could be. I mean I have been really moody lately. Always feel dizzy, having all kinds of headaches, appetite has changed, and having weird cramps to and all that. Just wondering what this could be caused by I'm only like 2 days late on my period and took a prego test about a week ago because I wasn't sure but came up negative. So just needing some advice please don't be mean or rude.