I use Depo Provera. It is the shot that you get every 3 months. So far it has worked just great...knock on wood
The only problem that I have had with it is that I gained a little weight when I went on it. But that doesn't happen to everyone, it just depends on the person. Also not to be too graphic, but when I first started on it I had "my friend" for like a month straight. But after that I don't get it at all. Some people don't like this but it doesn't bother me. Just like you I use condoms too, you can't be too safe.