You have to do what's right for you, but still keep in mind the feelings of other people. If there's something you feel you should do, like apologise, then go ahead and do it. If not, then don't.
I'm not sure of any social conventions for when you should/shouldn't contact someone after/before a break up for whatever reason, but I've never been big into social conventions. They just seem like a bunch of silly rules designed to keep people away from truth, love and power, perhaps for their own protection, or more likely: because people are often scared.
The fact that you think about her probably means that you have some unresolved issues. They are your issues though, not to do with her, so you can worth through them yourself. Are you completely satisfied with what you went through, and the lessons you learnt? Or do you think there's more?