Why Am I Bleeding After Having My Period?

I am a 45 year old woman. I was diagnosed with uterine fibroids in February of 2012. I was prescribed Loestrin 24 birth control for heavy periods. I took birth control 4 months. I stopped at the end of June of this year. I had so much weight gain from the pill, or so I think. I just started my period on the 28th of September, went through my regular period on Friday. And then on Saturday, I noticed I was starting to spot bleed again and started my period full and heavy this past Sunday night. I am bleeding bright red blood. I had breast tenderness in my right breast last week.