Cervical polyp

During my pregnancy my gyne found a cervical polyp. I'm now 4 month post partum and having the polyp removed in a few weeks. I've yet to have a period as breastfeeding but my lower back and lower abdomen have been painful for 6 weeks as if expecting my period. I also have a lot of discharge. Had antibiotics and nothing has worked. Is this all caused by the polyp?

Anyone experience discharge and pain with a polyp