Hi lisa_w - how old are you and what are your periods doing? If you are starting cyclical HRT then you start on the first day of the next proper bleed which counts as Day 1. If your periods are very infrequent then start at any time, but if they are frequent eg approx 3-7 weeks apart then wait until the next one - just a rough guide.
However if you are having FSH levels redone then have you been asked to delay starting HRT until after then otherwise you will not get a true result? When you get them repeated and if you have not started HRT you need to make sure they are done on Days 3-5 of the cycle. Day 19 means the level could have been high due to ovulation. If you are approx aged 40 or under you need two tests anyway 4-6 weeks apart to confirm peri-menopause.
No need to be upset - you will find out all in good time and be able to start treatment at the right time for you. However the surgery should have spoken to you about them. Perhaps you could phone the practice and ask to speak to a doctor at least - after all you should be entitled to an explanation of your results?!
Hurdity x
