I took primolut n in aug for 15 days continuos and 4 days after stopping got my periods on aug 29th... we had unprotected sex on sep 14th and again on sep 29th... after the intercourse on 29th I started spotting immediately and 4 days spotting was there during different times of the day,also cramps and back which is usual for me in periods. After 4 days spotting stopped And cramps also stopped. We did a home pregnancy test 4th oct and it was negative. Confused whether I am pregnant, what's the reason for spotting after intercourse for 4 days and negative pregnancy test?