implantation bleeding?

This is the first day of this and I still have sore breast and my period is not due until the 12/30. I am also not cramping really at all and this morning it was like a reddish color and now it looks like this..

going to take a pregnancy test when it is over with but wondering what everyone else thinks or has seen when they were pregnant. We have also been trying for a year this month so hopefully this isn't a period and I am a little worried that it is. I have also been having pain during sex but I'm wondering if that is a yeast infection.