Nope.
If I broke up with a woman, it'll be for a damn good reason.
What you're experiencing is what I like to call "dumpers remorse", where we create a picture of what an amazing person this "ex" was, while in truth the reality was somewhat different.
I can gaurantee she's thinking about you, but somethings stopping her. Maybe she's smart and knows YOU dumped HER for another woman, and has no interest in you.
Women who do this, tend to be women who have options. Maybe they already have someone new, and maybe have many suitors in line.
It's life. You have to close your mind to her, and move her on, because even if you did get back together, the problems from first time around, are still there.