I'm confused.

Okay, so I'm not exactly sure when my last period was. No clue, not even an estimated guess as to when it was last month. But a fee days ago I could have swore I started my period. I was in the shower and a little blood ran down my leg (TMI!) so, when I got out I grabbed a tampon. The next morning, nothing. And it's been about a week since that happened. I haven't had any cramps or anything, but I have a horrible headache right now. My boyfriend and I don't use protection and he pulls out but I know pre cum is a thing. I don't know if I should test, wait or what. Opinions? Thanks!