"help! i took plan b on october 28th, 3 hours after an incident my bf and i had. i got a period about 2 weeks later on november 12th. it was lighter and i didn&#039;t have cramps but still it lasted the same amount of time they usually do. my periods are very irregular. i had a period on july 14th, august 15th, september 22nd. i did not have one in october.. my last period was the one after plan b on november 12th. i took a pregnancy test on november 28th and it was negative. i&#039;m worried sick because i haven&#039;t gotten a period this month!! i don&#039;t know if plan b worked or not!! i plan to take a test as soon as i can but i&#039;m worried. is this normal?? "