i am 21 years old and sexually active. my last period started on 18th april and is still going on. It is mainly clots. But not very heavy flow. I usually last 5days. After the normal 5days flow has been light but continuous. No pain though. i wanted to know what might be the cause for this? this has happened for the first time to me. sometimes my periods get delayed maximum by a week. But not often. i did not hav unprotected sex in the past 1 year. the last time was on 11th of april but we used protection(condom). i still took a urine pregnancy test on 30th april which was negative. i have not taken any kind of birth control pills in the past one year. though i had food poisoning recently(almost a month back) for which i had 4doses of medicines prescribed by the doctor. Also can tension be a cause for this? As there were some personal matters around a month back leading to a lot of tension. thank you.