oct 31 had hummping sex nov 2 took next choice one dose the morning after pill i wason birth control for two months and stopped nov 16 got my birth control period nov 12-16 i took to pregnancy test one dec 9 and one dec 12 both neg then i got my first real period dec 12-17 now it ,y second period off birth control and and it is on and off and spotty it came on the first two days normal then the 3rd  and 4th day not at all now the fith day it back on but it only spots  and alot when i whip it also did this when i got my frist period off birth control dec 12-17 why is this what is wrong