So had to come off HRT 2 weeks ago whilst I await a hysteroscopy and biopsy on Friday. Have had so many bad headaches and migraines since. I used to get a migraine just before a breakthrough bleed after the progesterone part of the cycle now can't shift them and having more bad days than good. Hoping that post op I'll be able to go back on HRT - but is this normal? Is it the lack of oestrogen and progesterone that cause it ? been on HRT for 2.5 years and love it ! not sure what I'll do if they say I can't go back on it ! I'm an emotional wreck now as well !