relationship kharma

Is kharma supposed to be a good thing or bad? I'm not really sure. I just know I have a fear of the reprecussions of my actions and choices. A friend of mine once said she believed in the idea of relationship kharma. Meaning that the choices we make in one relationship, will come back to affect our next one (usually in a most negative way).
Last night I initiated my first "talk". Not the kind where you define where the relationship is going, but rather where it is ending. I tried to avoid all cliches such as "it's not you, it's me" or "I think you are a really great guy, but..." Unfortunately for me, all such cliches were true.
I've never been the one to end a relationship. This isn't to say I'm always being dumped. Sometimes the dating relationship mutually ends. Both people grow bored. Or one person moves away. Sometimes to another country... There are lots of reasons a relationship or potential relationship is ended.
All I know is that as the one who ended it, I'm very worried about relationship kharma. If in fact, I've hurt someone, does it stand to reason that I might get hurt in my next relationship?