Started period while on the pill???

Jessica • Silas Riley ~ 08/12/15 ❤️👶🏼
Okay so ive been on the pill before (for several months) and everything was fine, i got my period when i took the sugar pills, everything was fine. I had a baby 4 months ago, and ive been on the pill, i was on my second packet and i skipped the sugar pills and then i got my period? At first it was dark brown blood then it got more and more, then i just stopped the pill because i thought something was wrong, now its like ive got my normal period :/ what does that mean? Me getting my period while on the pill, 4 months pp