birth control after pregnancy

Colleen
I'm not due for another 4 months or so (May), but I've been trying to decide what to do about birth control. Husband and I are undecided on another at this point, and we both don't want an "oopsie," not that's there's anything wrong if that does happen, just don't want to have two so close together, especially if we are undecided on another. Any who...
-I had the Mirena before...no issues but I feel like it kind of screwed up my fertility when I got it taken out. And I'm afraid with after having my first it will fall out easily. Anyone experience this? Or get Mirena after birth? When do they let you go back on birth control again. 
-I've also been considering Nexplanon. Anybody ever use it? What's your take on it? 
- Used to have NuvaRing but it diminished my sex drive. So no go on that one, but what about the patch? 
Any suggestions on birth control? After you give birth...when do they allow you to get back on birth control? Immediately or do you have to wait?