NOT REALLY SURE, NEED SOME HELP.

I have been reading up on pregnancy, as far as to like how long does it take for implantion. I would really like some help on this. I ovulated March 22-29 that was my fertility window. Had sex on the day before ovulation and the day after. Went to the restroom on the 4th of this month & there was a little bit of blood. The next time u were, there was nothing. I am suppose to get period on the 12th of this month, but I'm just wondering could that have been implantion bleeding?