FS thought natural FET would work for me but it hasn't so I'm now on day 2 of HRT. I have been taking progynova 2mg 3 times a day. The nurses told me this is to build up my lining. No bloods are taken over this time and I have to go back fri 17th to have a scan. If they are happy with the lining, then we will transfer 4 or 5 days later. I have severe PCOS and don't ovulate on my own so I don't know if different steps are taken for others. Hope that helps! Good luck!