there's one catch.. i'm a girl
There's another catch: pęcherzyk in Polish also means bladder, the one that has to do with peeing :) That was my first understanding of your Polish sentence. It may also mean blister, especially one that is similar to those cause by skin's exposure to high temperature.
bubble, with the meaning you probably intended, would be perhaps bańka, banieczka, kulka, kuleczka.