Retin-A + Birth Control Q&A

I developed some hyperpigmentation recently, and I've learned that birth control could cause that. I've since stopped birth control, but I want to get back on it; someone told me stopping birth control doesnt help get rid of the hyperpigmentation but my question is would going back on it make it worse? Granted I was also really inconsistent with keeping up with my birth control and I think that may have been the main reason.

2. Do two forms of birth control need to be used with topical Tretinoin Cream (0.05%) as they do with Isotretinoin oral?

Im using Retin A/ tretinoin about 3.5 months now , but my pimples still keep appearing. actually it worked on me a bit now my face looks plump shiny and other part is soft but the problem is everytime i wake up in the morning im still having new pimple . its already 3 and half months since im using tretinoin but still didnt achieve the clear skin that i want . so i want to know if i use oral contraceptive will reduce the effectiveness of Retin A / tretinoin ?

I have the nexplanon implant in my arm for almost a year now and recently I started using Retin-A for my acne. Does the Retina-A decrease the effectiveness of the implant?

I am on birth control pills but my pimples still keep appearing. I want to try using Retin-A since when I used it before (without the pills), it worked on me really good. But, now it's back, so I want to know if the birth control pills loses its effectiveness if I use both pills and Retin-A?