I thank you for sharing your condition with me. It though seems pretty normal but could be somethingundiagnosed and of concern. I don’t want to scare you nor you should be things like this happen and you would be normal. What happens is that after such kind of Bacterial treatment, sometimes the lining of the uterus gets affected and could lead to vaginal bleeding or at times the period happens to come early due to the breaking of endopellium lining. It could be any one in your case but each one doesn’t carry any risk. How ever since you indicated sexual relations you should check your condition for any sexually transmitted infections. What I would advise you is to keep a check on it and if the bleeding doesn’t reduces or it does not seems to be the regular menstruation you could consult you gynaecologist who could by further testing to diagnose you case and examine your condition to give you proper medical treatment and also advice you on sexually transmitted infections in this regard. Don’t worry, you would be alright, there is no condition of worry.