Please answer this and help me!!!?

My ex and I have broke up and I've tried a couple of times to win her back and she kept say I don't know. The last time she said "I don't know, I'm gonna say no even tho I'm soo going to regret it" what should I do? I don't wanna push her away anymore. She often pops up and stuff and when she does we start talking how we used to and be flitghty but then she suddenly changes her mood and doesn't want anything to do with me. What should I do and how will I win her back. I'm going to meet other girl s and stuff. Will that help at all but I'm affriad of pushing her away if I keep poping back up. She saus she'll regret it and soo do her mates. What should I do?:( I know I should move on but if they was any way to win her back what should I do?