AF due 12-15

My AF is due 12/15 and we BD on both my high ovulation days with preseed. I was going to take a preg test this weekend but today I noticed some blood. It's not soaking my underwear at all but when I wipe it's there. Could it be implantation? I'm 10 days Past ovulation as of today so the timing would be right but the blood is red, not brownish. Help?!