I think I’m pregnant what do i do?

Cecelia

My little sister is telling me that she thinks I should take a test and find out if I am or not but idk what to do or how long I should wait...she also said that a few of our cousins had the exact same symptoms as I do but idk if I should wait till my period or if I should just buy two or three tomorrow and take one tomorrow please I need someone’s help!?