birth control and periods

So I'm on the 21 day pill with a 7 day break and within the week your period comes, stopped taking the pill Sunday and I normally come on my period 1-3 days after so today being the third day. Normally I'm accompanied by extreme pains to which I can't even get up but nothing not even a slight hint of a cramp. Is it possible I could of accidently concieved? I will give it a few more days to see if period turns up but as I'm not in any way ready to raise a child this is worrying me a little. 11 days ago I also suspected I was pregnant as I had a few signs including frequent urine, back ache, extreme breast growth, sore breasts and nipples but thought nothing of it but now I'm getting a little nervous. Sorry for the long post .