Tell me something....

So I have had no symptoms, dilation or anything. Last night, I began have some contractions in my butt for about an hour off and on. So today hanging out with my mom, when I got home, (yes completely unprepared) I went to the bathroom and there was about a quarter size of blood in my panties, not a clot or mucus mixed or anything, just some blood that looks like it was soaked up by my panties.

I am 39w2d today. Could this be the beginning of labor to come? Or could thus be something else? I did call my doctor's and waiting for a return call.