I am on Yasmin BC and I have a brown/red discharge while on my yellow pills...?

So I have been taking these pills for 2 months now and I had my period regular after the first pack. Now since on the 2nd pack I now have this brown/red discharge only when I wipe and I thought it would be my period since the next day there was a little blood but nothing to get all excited about. Plus this is happening a whole week and a half before I am suppose to have my period. Does this mean that I am pregnant or is it just something that happens while on yasmin BC?