Medical question, need help, has to do with birth control and a rash...?

It is day two that i have just taken the birth controll trinesa. i take it at 9 pm and today (day 2) around 11 am i noticed my arms were itchy, just my arms, and that i had tiny red bumps when i itched my arms, otherwise it is unnoticable unless felt. now it is 6:30 and it started a little bit on my lower back. It says a rash is a side effect of the birthcontrol and to contact my health profesion if it bothers me but alls i have is a pediatrician (im 17), how do i get rid of it, do i have to stop taking it? i just spent alot of money on it so its prerfered that i dont stop taking it...what do i do? how do i get rid of it?