Okay I'm on birth control and I didn't take a pill Saturday or Sunday (this would be the week my period was to start so I wasn't to take a pill) and then I had sex Sunday night it was unprotected but he pulled out but I was still worried so I took plan b on Monday! It is now Thursday and I haven't started my period yet. I've heard plan B can delay periods but I'm not sure if I should be worried or what I should do?