I took plan b and about a week later got what I thought was my period, this one was much shorter (about four days and my normal period last about 7) two weeks later I got a period that lasted the full 7 days, a week later I am nauseous and cramping, cou

Effects of Plan B... Irregular bleeding after taking a morning-after pill, like Plan B, is somewhat common. Some women get spotting or bleeding before the next period. Women may also have a heavier or lighter next period, or a period that is early or late. A urine pregnancy test can be done 3 weeks after taking a morning-after pill, to be sure the pill worked.