Did you gain weight using Implanon?

I used to be a size 4-6 when I got the Implanon I went up to a size 14-16. My doctor told me it had nothing to do with the birth control. However when I chose to switch to the pill I haven't gained anything. My weight has just stayed the same. I never changed eating or exercise habits. I'm just wondering if I'm the only one the experience this, with this form of birth control