Periods?

So I'm a first time mom and had my son November 3rd and bled off and on most of the first 8 weeks. Had a break and then started having light bleeding December 30th, then it went brown and then my husband and I had sex and that I guess kicked the full blown period into affect and that went on for a few days and then it lightened and went away in 7 days like a normal period. But if it was a normal period I would start at the end of this month but I'm having a lot of brown discharge again and it's freaking me out. I'm on the pill and breast feeding. But I'm just wondering if anyone else has had this happen to them.