Despite all my best plans to wait until tomorrow to test, and then only if my temp went up again (it dropped to 36.5 today), I couldn't resist and tested this morning.
I had a tiny bit of spotting too, so unless my temps stabilise or pick up, I'm guessing I'm on the road to AF again. In the meantime I've made it hard on myself by testing too early despite being big enough and ugly enough to know better.
Anyway, I'm sitting in the doctor's surgery and am finally getting up the courage to ask for help again, albeit as an aside to another issue. I'm not sure how far I'm prepared to go with assistancthis time, but maybe there's something else I could be doing.