Hi ! Good morning. i am Dr Shareef answering your query. If you are active sexually all these days, I would like to advise you for a routine urine test and a culture sensitivity test if need be to rule out a UTI. Apart from this, you might have to go for a serum HCG estimation followed by an ultrasound abdomen to rule out an unsuspected pregnancy, even though you might be observing some contraceptive precautions. Last but not the least, it might be simply a spontaneous involuntary strong contraction of the uterus post coitus without any precipitating causes. I hope this information would help you in discussing with your family physician/treating doctor in further management of your problem. Please do not hesitate to ask in case of any further doubts. Thanks for choosing health care magic to clear doubts on your health problems. I wish you an early recovery. Dr Shareef.