I have been feeling cramping and bleeding for 4 days. I had an UTI 2 weeks ago and was treated w amoxicylicin. I am take birth control pill.?

Cramping /bleeding. Would check HCG. Antibiotics can lower effectiveness of BCP. may be infection like yeast or other like mycoplasma/ ureoplasma, BV also from use of antibiotics.Follow up with doc/urgent care.