I took plan b on Dec 19th, and the start of my last period before I took the pill was dec 3rd. I experienced a bit of blood spotting five days after and presumed it to be a side effect from the pill. Two weeks after taking the pill, and exactly one more after my last period, I got what seems to be my period because it was pretty heavy and I had experienced cramping. However, on the third day, the flow seemed very light which is unusual from when I do have my regular period. My period is usually heavy the first three days btw. Should I be worried or is this just a side effect of the pill?