What are my odds of running into my ex girlfriend & how to dealing running into her?

It's clear she does not quite enjoy your company. "No time to hangout" and she's seen with a co-worker? I always tell guys I don't really care much for that I don't have time to hang out. I suggest you find some other friend to hangout with and just let this one go. If you want to be her friend then wait until she calls you up or wants to hangout, but don't ask her.