Higher than they are in non twin families. It was said that only two egg twins run in families but now it is also said that one egg twins can too. But that does not mean you will have twins. But it does mean that it is more likely that you could.
I'm pretty sure you will have twins..maybe not your first kid..but if you continue with pregnancies you will most likely have them..but they do say that twins skip a generation..so I'm not sure but it sounds like you will..