What's the best birth control?

I'm going to start birth control soon. I'm a freshman and my mom just wants to make sure that nothing happens in the future. I want to get the little implant in my arm that last five years. But people say it makes you gain weight. I know it would depend on the person but I don't want to risk gaining weight and being uncomfortable with my body since I have body image issues already. I'm not very good with remembering to take my pills so my mom doesn't really want me to go with that. Any suggestions?