I've been on microgestin Fe 1/20 for about 5 months now. I had unprotected sex about 5 days ago and my period (or so I think) just came early. I have been experiencing heavy cramps for the last few days however my bleeding is extremely light and brown. I have been reading up on somethingg called implantation bleeding Which tends to happen a few days after sex and I want to know is this is that bleeding or just my body adjusting to the birth control still. In the 5 months that I have been taking birth control pills, I have never had such a light period before (if this is even what it is). However, the cramps are definitely very similar to menstrual cramps.