<s>[INST] I am taking Amoxicillin 500mg x3 a day after having a chest infection a week tomorrow my last day of taking them is tomorrow, however I am on my period and the pain is awful and it is not a normal period it is just blood clot after blood clot I have never had it before and is really painful. Is it normal? [/INST] Hi,Amoxicillin is unlikely to cause blood clot during menses. Chest infection can act as a stressor on the body which can cause menstrual irregularities such as passing blood clots or having painful menses. Once the infection is eradicated you will resume your normal menstrual cycle. Complete the course of prescribed amoxicillin. However, if bleeding continues I would recommend you to consult a gynecologist to rule out other causes of passing blood clots.Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Mohammed Taher Ali, General & Family Physician </s>