I am on the birth control pill and missed one pill right inthe middle of my pack, and had unpotected sex that night (no condom). I took the pill the next morning as soon as i realized i had forgotten. I had been told before by a doctor that the pill stays in my system 24 hrs after i am due for another one. It is one week before my period now and i have had menstrural like cramping the past two nights, but they did not last long. Should i be worried that i am pregnant?