If it comes out slow, check the screen. When water is turned off from the city workers, or a plumber in your house doing work, it can force rust into the screen when turned back on. My old apartment put in a new boiler, and my faucet got clogged up.
It is possible if your tub is draining slowly that you have a clog. After your bath, pour about 1/2 a bottle of Drano Max Gel down the drain and let it stand overnight. It will help dissolve any hair, etc. slowing down the drainage.