Weird Birth Control question

Ren • 17/engaged/anti establishment/ Howl ate my heart ✌️
So, I'm not sexually active, and I won't be till me and my fiancé get married. BUT it's never too early to start thinking about what we're gonna use. Here comes the weird part....
Is there any birth control that:
1- isn't gonna make me gain weight and grow boobs and
2- is non "abortive" (I seriously don't mean to insult ANYONE or condem. This is just MY personal preference) and by that, I mean, no preventing of attaching to the wall, no terminating the fertilized egg, ect. I guess what I'm looking for is something that prevents it BEFORE the fertilization happens. Again, not in an offencive way, I'm just curious :) 
Much love!