I enlisted into the Navy and chose a rate/ is it too late to change my rate?

I recently enlisted into the Naval Reserve after going through ASVAB tests and scoring a 95. Before I enlisted I decided to join up as an STG (both my grandfather and uncle were STG in the Navy) and then commited to that rate. After actually doing research on different rates, I decided that I'm more interested in the CT rate (I'm multilingual). I've trolled through some of the forums here and just want to confirm; while I'm in DEP I've got every right to change rates before before swearing in at boot camp correct ?