Curious.

AF was due on Sunday, and never came. Not even a symptom. my boyfriend and I took advantage of this and had unprotected sex 3 times in the last 3 weeks and he came inside of me once...This morning I woke up with an uncomfortable feeling. Almost like AF cramps but for sure not anywhere near as bad as they normally are. So I got up and went to the bathroom and 2 drops of blood came out while I peed. Normal period blood colored too, not light pink, or brownish. If anything it was even a little darker than most would say. 
I haven't tested or anything. But is it possible that maybe this is implantation bleeding and cramping? Or just a very odd, unnormal start to an almost week late AF?