I started in one pump Ali feuded Mirena, then upped to two as I was still getting hit flusges and anxiety, now I use three as it helps my VA symptoms.
When I had Mirena fitted by the gynae at the hospital she wrote on my Mirena infir, remove/replace after 4 years.
When I spoke to my GP a while ago, she said 5, I think I prefer to take gynae's advice, my GP also said, if I decide to stop HRT, I don't need to have coil removed, it's fine to leave it in! ....I don't think so!
I'm sure she only said that because my coil strings have disappeared inside my cervix (had scan as couldn't feel them) and she knows it possibly won't be easy to remove it.... I've got until December 2019 with my current coil, so will have to start thinking about it next year 🙄