Best birth control?

I am currently pregnant but am looking to get back on birth control after the baby. I was on the pill before and I took it religiously every morning at the same time. It failed as I got pregnant on it. I know it's not 100% effective so it's my fault. Anyway, I know I'm going to be very busy with the new baby and might forget to take the pill daily. What are my best options? I know there's a copper IUD, nuvaring, Mirena, and an arm implant. What would you guys suggest?