Hi, Thanks for the question! Heavy antibiotics do not cause such discharge, but the stress related to the infection may cause hormonal imbalance and alter the menstrual cycle. In any case, there are certain other conditions like infections of the cervix or vagina, any tumors on the cervix or uterus may also cause intermittent bleeding and these need to be ruled out. When women with similar complaint walk into my clinic, I perform a vaginal examination to see for infections or tumors, do a pap smear to screen for any cancer and if needed get an ultrasound done for any causes in the uterus. So I suggest you do not attribute this to antibiotics and get yourself examined. Hope this was helpful. Thanks for the query and for using health care magic. Dr. Madhuri Bagde Consultant Obstetrician and Gynecologist