My last period was on April 23rd and ended a week later. Then on May 3rd I had unprotected sex (I'm not currently using birth control), and according to some website, that was my best day to conceive. So I took Plan B, emergency contraception later that same day, and then yesterday, May 8th, I started what seems like another period, except I didn't get the warning signs (like a twinge of pain) before, and it's lighter than it normally is, but definitely not just spotting. I did have some slight cramping after it began. I looked up more info and it could be breakthrough bleeding, but I'm fuzzy on the details of when that can happen or if that's what it even is. My period has always come regularly with no problem, and this is the very first time it has come this early. I was expecting it to come on the 23rd give or take a day or so, and it came the 8th? Is that weird? Is that just breakthrough bleeding? -- I've also read about women who have had bleeding similar-sounding to mine during the beginning months of their pregnancies, so I'm just not sure what to think it is.

Maybe its because of the emergency contraception? I think it may have been to soon for you to be spotting (pregnancy spotting). I'm not sure but maybe you should get a pregnancy test and see your ob/gyn just to be sure