You don't have to use the same locker room if you're going to the pool, you'll spend all of what, 10 minutes in the locker room? It's not a big deal. Each of you should use the one appropriate to your current presentation.

I am starting a new university in the fall, and it's a tiny campus, and I worry about the same thing. I think I will start off the first day using the men's washroom I guess. But the people there know I am trans, so I wonder if I will have problems.