Took Pills, Missed 1 Early On In Cycle.

I'm 20 years old.

As of right now i'm on the placbo (green) pills... And it's day 3, and I don't have my period yet. This is my first month on the pills, and I started immediately after my period stopped, so protection should have started immediately, right?

Anyway, I did miss one pill, and took it the next day. It was early in my cycle. During this month, my boyfriend and I had unprotected sex several times. One time for sure I know he came inside of me, and there may have been a second time.

Is it really possible i'm pregnant? Or is my period just being stubborn? My period is normally on an almost 40 day cycle (35-38 days apart). I am very slim, even for my height. I'm 5'2" and I weigh about 97-100 lbs. Also, my periods are usually very light lasting 3 days on average.

When I was on the pill years ago (when I was 16) I believe my period always started the day I started taking the placebo pills.

I did miss one more pill right at the end of my cycle, but my boyfriend and I had not had sex for several days. I think we had sex after that, but he pulled out before he came. I missed the pill right before the last blue pill, so I took those last 2 pills at the same time, and then started on the placebos the next day. Could that be why my period is being late?

I think i've felt some pre-cramps, which I sometimes get a day or so before my real cramps and period (my cramps are regularly very painful). But i've heard that the pill can lessen the pain of cramps. Alright, i've asked a lot of questions, hopefully you can answer the most importnt one:

how likely is it that i'm pregnant? Do other women have periods that start late when they are on the placebo pills?