I had sex with my girl friend unprotected. when i pulled out, i made sure that no cum got in her. that was a week ago. now she said that she may be pregnant. what shouldi do?

It's possible: On rare occasions, pregnancy may occur. She should undergo a sensitive pregnancy test if she thinks she may be pregnant.

Pregnancy 7 days : If she knows she is pregnant, then it probably is from another sexual encounter, as a pregnancy 7 days after intercourse would not be likely to have any signs or be detected by ordinary pregnancy tests.

Only takes one: There is often some semen in pre-ejaculate, so the pull-out method is not very reliable. However, if this was your only encounter, it is not likely to know pregnant after only one week--more like 3. Perhaps another partner?