My period is always due on the 18th of every month, this month it came on the 10th. It was very light but still blood. Not NEARLY as heavy as it usually is. I still had the period cramps. The second day, towards the end it almost completely stopped. Me and my boyfriend had sex on the 3rd day and it came back on the 4th, then stopped again. And I had very like pink to brown in the morning of the 5th day and that was the last of it. I have no idea whats going on. Please help!!!