Alright, so my girlfriend and I ended up having sex around a month ago, but since then have broken up, but still kept to being friends, and we still talk fairly often.

Anyways, my question is.. while I was talking to her these past couple weeks, She mentioned feeling sick and throwing up two seperate times in like a 2-3 day time period, but without being sick.. and recently said she woke up with a headache and had to throw up.

Is this a sign of early pregnancy? Or am I just being overly cautious?