I find humor helpful in these things, because the default is head-holding drama. Next time you talk, and she asks you what you've been up to, say something like "Oh, just updating my jdate profile." It will help diffuse the awkwardness, or at least it has for me in the past. In any event, good luck.
Yup. Don't be the guy who responds to that prompt with talk about how much you've been dating/spreading your seed throughout New York. By the same token, don't give her an opening to boast about her own dating/sexual conquests since you've been apart.
This all sounds like common sense, but some guys and gals can't help but add insult to injury by talking about the above, even if they were the ones to initiate the breakup. "Oh hey, I know I dumped you, but since then, well I had a pregnancy scare because I let this guy hit it raw dog too often."