PhD students transfer all the time. I did. In my case, my advisor left for another university. Following her wasn't the best choice for me, and neither was staying in the original program, so I transferred to an entirely different school...
While I think seaweed gives some good advice based on personal experience, it's one thing to transfer because one's adviser is going to a different school and another thing entirely to decide after two months you want to leave.
This is my fourth year in my program and we've had exactly two transfers at the Ph.D. level. One was a girl who was accepted at a university in her home state but came here because she got a better funding offer. After one year here, someone at Home State U dropped out and she transferred taking his funding slot. The other is someone who transferred because her adviser was hired away from another university.
Anyway, whatever you do, do NOT say that this year was a practice year (as you intimate in your OP). You need to develop a coherent rationale to present to the admin committee for why you fit into their program--and the rationale needs to be strong enough to overcome any initial worry about a transfer.