I need help choosing a form of birth control

I recently became sexually active and I have and always will use condoms but I want to be sure I don't get pregnant and I want to start birth control as soon as possible. The problem is I am really not okay with telling my parents I'm having sex Bc they are very strict and would flip out. Luckily my boyfriend is a great guy and would totally drive me anywhere I need to go and support me through it all but I need to try something I can keep from my parents so nothing that would go through our pharmacy or my parents insurance or require parental consent. Also I've struggled with eating disorders in the past and going on something that would make me gain a lot of weight could cause a relapse so I'm really trying to stay away from that