It's possible to have twins even if there is no family history. This would be especially true if you are using Clomid, because for non-identical twins you need to ovulate twice in a given cycle and this is more likely to happen with such help. But it happens to lots of women who aren't on anything.
For the record, identical twins are just a chance occurrence, whether there are other identicals in the family tree will not affect the same thing happening again. Non-identical twins can run in families, down the mother's side.
thanks, but not useing anything, just wanted to know what the chances were.