it's not possible right?

If you've had two cycles. The periods were 5 days each. The first two days heavy, third medium, fourth light, and fifth light/spotting. You're on the pill. You use condoms except for one time he put it in twice without one on. You've take one test before your last period on March 28, started the 29th. It ended April 2nd. Taken three after the period. All four tests negative. Is there anyway I could still be pregnant? My boobs/chest have been warm and red but I'm currently having seasonal allergies. I'm extremely stressed out and upset over this. I feel alone and cry all the time. I can't tell my parents. Everyone keeps telling me I am fine.  I think I've actually scared myself into having symptoms.