Contraception and breastfeeding

Baby is currently 28 weeks old and I am still yet to choose a contraception method, playing with fire I know! We are currently just using condoms.

My periods returned around 10 weeks post partum, and they’re every three weeks lasting around 3/4 days. I fell pregnant on Feanolla (progestogen only pill) so I refuse to go back on the pill full stop. I don’t want to have an IUD as I think ten years is too much of a big commitment, although I am aware you can have them removed before the stated time.

I have had the Nexplanon implant twice before when I was younger, and I’m swaying to have that again, especially because my periods completely stopped, although I don’t mind them.

I’m just worried my milk supply will diminish! Is there anyone with the implant and noticed there were no changes with your milk supply, or can anyone recommend the contraception they use that doesn’t alter their milk?

Thank you.