I'm currently on treatment for pcos and have been getting my period consistently. this month, i had to take antibiotics for a sinus infection and now my period started 4 days late, is light & painful. should i be concerned?

PCOS ?'s: "Treatment for PCOS" is generally done via oral bcps. Antibiotics can reduce the absorption of the hormones in the bcps, causing withdrawal bleeding from formally ingested oral bcp's. It is unlikely, but possible for spontaneous ovulation to take place, so pregnancy is "possible" even with PCOS. Obtain a serum HCG test to be certain about pregnancy.