Birth control

Hi all,
​I was curious if anyone knew of the best birth control that will not make you gain weight. 
​I love my body and I'm in the works of getting more toned. So I am scared if I start taking a contraceptive my weight will increase. 
​I am very sexually active right now with my boyfriend and I do not need the risk of getting pregnant. 
​Condoms work great but I prefer a safer route.