Just to chime in and say since being on HRT I've never been able to do a finger **** test through Medichecks without it being contaminated - I've wasted a lot of money. I even wore plastic gloves for two weeks to apply, and it was still contaminated (and with Lenzetto it's not even like you rub it in with your hands!). Medichecks are fantastic but if you're on HRT I would highly recommend doing a venous blood test so as not to waste your money (as you don't get a refund for contamination). It's really simple and easy - just choose that option at check out and select from a list of local clinics, Medichecks send you the box, you take the box to the clinic and they do the test and you post it off to Medichecks. Results usually in 3 days. Cost for Estrogen only is £79 for a venous test.
In general I have found blood tests absolutely critical for me correlating and understanding things, and have been frustrated at the GPs lack of ever saying they will to do one (though do totally understand there is a limit to what the NHS can pay for). I agree that symptoms are the most important to treat on, and if you're still having periods (which I know you're not) you need to do them at the same time of your cycle to compare. But they have been crucial to me in my experience! Good luck Hannah, keep us posted!