I think that my first boyfriend like another girl??plz hlp mee?

im going out with this guy. i really like him and he asked me out about a week ago. but i found out that she kinda flirts with my friend. i know she doesn't like him anymore but they use to go out but she dumped him. also he hasnt been calling me back when he said he would. i was thinking about dumping him, but i really like him and there aren't many guys at my skool. plzz hlpp