What is the best birth control?

Hi, can you help me please? I’m 16 weeks pregnant with my 2nd and thinking already about which contraceptive method we will use after the six weeks postpartum; I’ve been thinking and researching for nexplanon, and I was 100% sure about it, but now I don’t know if it’s the best, I reed that may I gain weight, and I wanna lose some weight, I’m like 5 pounds over my weight, and I want to lose it cause I will get married on July 2022, so if you can tell me your experience with nexplanon or the method that you currently use, it will help me before I make a decision with the help of my ob/gyn