Hi i had a heavy period last month and now i am 4 days late this month. I did not have sex this month. I have been having period cramps past two days. I have been exercising strenuously past month for an hour almost everyday and my diet has changed too. I havent gone to the gym past two days because of my cramps and feeling tired. I have slight headache on and off too. Its a very uneasy feeling and what medication can i take? Also i was sexually active last month but then i got a heavy period like i mentioned. Can you please advise whats going on?