Best birth control

I am 26 yrs old me & my boyfriend have been dating for a year & 1 month. We want children but I feel like we r not where we need to be yet to have any....Guess u can day I am trying to be the "responsible one" my boyfriend wants a baby badly!! I've heard mostly every birth control makes u gain weight along with other side effects, what is a good birth control? Want to bring it up the next time I see my doctor to see what she says. There's day when we make love we really get into it & I don't want one of those good love making days/nights be the day we find out we r having a bundle of joy?