Birth control help - arm Nexplanon or IUD

Need advice on birth control options! For years and years I took the pill. Got off. Had a baby and then never got my period back. (I was always very regular prior to baby). Then out of nowhere I got pregnant 7 months after having my son. Before we make the permanent decision for my husband to get a vasectomy, I'd like to get on a long term birth control. I dont want to take a pill daily. I dont know why but IUDs make me nervous. But I'm open to it. I've always been interested in Nexplanon the arm implant. Basically I need as close to a 99.9% accurate birth control!