K.P.
The rate of success of reversal depends on numerous factors, including the type of sterilization procedure you had. You can call the office of the OB/GYN who performed the procedure and ask them for specifics, because they will probably have better information. It may be that your particular kind is irreversible. I've not heard of having tubes "clamped" before, so I really have no idea whether it can be reversed or not.
Another possibility that you may bring up with your doctor is in vitro fertilization. Although you're not technically infertile, you may be able to use fertility treatments in order to get pregnant. I've not heard of this before, but it seems possible and logical to do. Many infertile women will have their eggs harvested from their ovaries, fertilized in a test tube, and then have the embryos transferred to the uterus. Obviously, this can get pretty expensive, is a huge hassle, is not without risk, nor does it carry a guarantee of having a baby.