Contraception whilst breastfeeding

[Etak15]

After having dc 4 six months ago and exclusively breastfeeding now he's gradually getting into his food and sleeping for longer stretches at night, I am thinking I need another method of contraception apart from breastfeeding It has worked for me previously and I have a 2 yr gap between all of them using no contraceptives breastfed others till 18 month ish, but before I knew that I wouldn't mind if I became pregnant - now I would mind!! Any recommendations? And why are some contraceptives unsuitable for breastfeeding is it harmful for baby or does it affect milk quality?

I think it's to do with certain hormones affecting milk supply. I'm looking into this as well and from what I understand progestogen only contraceptives are okay. So the mini-pill, injection, the coil (I think) and the implant - which is what I'm considering using since I can then forget about it for 3 years. Maybe some others but those are the ones I remember off the top of my head.