Help with a period/pill problem?

Ok so here's the deal. I have been on alesse for about 4-5 months now with no problems (I switched from another brand to allesse). I am on the 28 day pill pack, but after starting the active pills again today (Sunday) like I was supposed to (I had a normal period during the placebo pills which began early tuesday and ended thursday (short, but normal for me)), I had a quick bout of heavy breakthrough bleeding. Is this normal seeing as how it's only the first day of the active pills and maybe it's just because it was not quite finished? Thanks for the help :)