Unusual start of period of implantation bleeding?

I apologize if TMI.

Last night, my cm had a very light pinkish tinge to it with a single spot of a darker pink. I didn't think too much of it, just that I would watch it before I went to bed to see if it got worse. But when I went in next to check, there was nothing. I pushed it to the back of my mind and went to sleep. This morning, I decided I would check again just to be safe. Still nothing. I've never spotted right before I got my period, and I also don't have any of the other symptoms usually present when AF comes to town which is expected to be tomorrow. Is it possible that it's just an usual start to my period or could it be implantation bleeding?