Breastfeeding-safe Birth Control

So this has probably been discussed before but I can't seem to find any recent discussions: I have my 6 week pp check up next week and I am still very undecided on which birth control to choose. I'm currently torn between the hormonal iud and the implant. I'd appreciate any input or advice on your experiences (side effects, weight gain, milk supply, periods, etc.) or if you prefer a different form of birth control. Thanks!