The Mirena with seperate oestrogen as pills, patch or gel is a great HRT combination.
The only thing you need to do is make sure the Mirena is changed every 4 years when using it as part of an HRT regime. If you look under TREATMENTS on this site, in the progesterone section, you will see all the info on the Mirena as part of HRT.
Enjoy feeling better once the oestrogen kicks in. DG x