On the Mini-Pill!

Heaven
I only get my period about every three months because of my pill. I've been taking it on time during the week and a little late during the weekends. Two weeks ago I took it late like 5 days in a row and had brown spotting/discharge. I took a pregnancy test just to check and it was negative. My partner and I always use condoms. I had more brown spotting/discharge today after taking a pill late. I'm not supposed to start my period for 10 more days. Confused. Advice/Answers??