Ive been on birth control pills for 3 years now. My flow had always been heavier but my last withdrawal bleed was really light for three day. Only enough to fill a third of a tampon each day. It did come on time though. I am now on my second week of my new pack and am experiencing period like cramps for about 4 days now. I am just wondering if this is normal? I did have unprotected sex last cycle but have not this cycle.