I have been on the pill for four months and take it at the same time every day. My boyfriend and i use condoms as well. But last month we had unprotected sex on my first day of placebo pills and he ejaculated inside me. Two days later i had my period which was at the normal time. But this month i've been feeling nauseous at night and i feel a little 'knot' in my lower abdomen. I'm not sure if all of this is because of stress or just side effects from the pill, but i'm a little worried. My next period is due tomorrow, but im super scared it won't come. could i be pregnant?