brummiemum, that's great news! So glad all is ok 
barking, glad you've found some local support, and of course we are all here for support in bucketloads, but hoping you don't need it and will instead be beaming from ear to ear and shouting your bfp from the rooftops 
loopy, it was also my concern with the last two mc, but it's such a hard one. Like you, i am used to getting pg v easily so to have months where i didn't get pg or mc early was frustrating/upsetting. It seemed impossible that i could hit that many 'bad eggs' in a row (of course its not impossible though).
I really can't decide if the two early mcs were bad eggs that for other people wouldn't have got that far (in which case the prog still wasn't working correctly, as it should have stopped them before bfp), or good eggs that were 'contracepted'. Last month i was convinced the latter was true (hence why i didn't take it from 7dpo), but if I'm honest, looking back, this pg has felt very strong and different from mc5 (which felt weak) and i think that one actually might have been a bad egg. Mc4 did feel strong at the very start, so that could be either. I was terrified of starting the prog with this pg, but started at 14dpo as that spotting was actually freaking me out more than the worry of taking the prog. It stopped the spotting and doesn't seem to have done anything bad (although the jury is of course out until scan Friday).
I honestly think prog works differently for different people and that from 7dpo just doesn't work for some people, but i think once the pg is established i would no longer worry about it 'contracepting' anything (assuming scan is OK. If scan is bad I've pretty much decided i will not take it again.)
It's such a balancing act. If it's stressing you out more than its helping then i would def say to just take it from 14dpo (or not at all if you're worried). I think the main benefit from the Coventry POV is taking it early to make your lining selective, but if that doesn't work for you then maybe you don't need it at all?
Sorry for the ramble. I found it hard to be objective last month as i just wanted to get past 5 weeks, but it's easier to look back now and admit that mc5 wasn't as strong.