Birth control

Ashlynn • Married and mother of 2 perfect little boys with a sweet baby girl on the way- due in October 👻💕
I have an appointment for my 6 week check up on the 19th, and my doctor Said that we will talk about birth control and pick one for me then- only problem is I have no idea which one to choose! 
I've never been on any kind of birth I don't know which is best, or most recommended. I DO know tho that I don't wanna go with the one that's like inserted, cause I've heard ALOT of bad things about it. 
So what are other options for me, what would you ladies recommend? As stupid as it sounds I really don't wanna go on one that will cause me to gain a lot of weight..I'm already super self conscious about my body.. 
Please help!! ☺️☺️