Navy Corpsman FMF (reserve)?

I just recently Enlisted (reserve) and I am now in DEP. My question is concerning my contract. I have been reading a lot about the job I signed up for and one of the things I have read is that the specialty of FMF cannot be guaranteed. In my four part guaranteed enlistment contract it has as the fourth part FMSS-8404 C school. Along with the place I will be stationed. Have I been mislead in this contract or is that indeed my guarantee?