first... vegetarians don't eat fish... (or chicken or any other meat) so no, it is not vegetarian to eat fish
second... you can call yourself whatever you want but here's why you should continue telling people you are pescetarian and then explain what that is
because when you tell them you are vegetarian and then they see you eating fish they assume that fish is vegetarian and when and IF they become vegetarian they'll eat fish not knowing the truth
and fish feel pain just like any other animal and deserve to be saved too... just because they aren't cute or cuddlely like other animals doesn't mean they should be eaten
here's why you shouldnt eat fish
a) you have to explain to people what pescetarians are
b) if you're doing it for the animals, fish feel pain
c) if you're doing it for the environment, fishing harms the environment a lot
d) and fish isn't healthy... it has lots of mercury
e) and if you're doing it to be cool, being a vegetarian is "cooler" than being a pescetarian...