I had sex with my boyfriend but the condom came completely off as he was pulling out so sperm may have been introduced.

I took a pregnancy test a few days later and got on birth control and since have had a light period.

I've had pregnancy symptoms since then. (Nasuea, back aches, head aches, mood changes, etc.)

My boyfriend says he's sterile (because of his job and family history).

But I'm still concerned.

Is there ANY chance I could be pregnant?