Friend just called me wondering if she could be pregnant, what do you think?

Okay, so a little bit ago my friend calls me and starts panicking in such telling me about how her and her boyfriend were messing around...She informed me that he "just had the head of his rubbing for a few seconds" between her and . And then she followed up by bombarding me with could I be pregnant? Type of questions....I told her no, mainly because her boyfriend said that he was dry and probably had no pre. What should I do...do you think that saying no was the correct answer or should I call her back and tell her different?