plan b - how effective is it?

hi. im stupid and had unprotected sex.. and im not on birth control yet cause i was waiting until my next period so i can start using birth control pills again. but I didn't wait.. uhm.. I took the plan b -morning after pill.. is that still as effective as birth control? And is it normal for my period to be late? Yesterday, I was soo sure that  I had my period, cause I saw blood in my underwear.. but that was the only time I saw it, and not again. I also got cramps, so I assumed I had it. But now there is nothing, and I am just waiting to get it already. And since taking birth control pills can effect periods, could that be what I'm experiencing? I should be getting mine soon- maybe on Friday. but if I DONT get it on friday, is that ok? I dont know.

[JLB487]

If u spend a couple of dollars and do a pregnancy test your worries will be solved! They're cheap as anything! And it'll put you at ease to know and stop you from freaking out!