Metformin, and the earliest one can POAS?

For starters... a quick question about Metformin... How many of you were taking Metformin before getting pregnant to combat PCOS, and in fact got pregnant AND continued taking it throughout your first trimester? Last time... I took it, and I got KU, but then miscarried/had a chemical pregnancy relatively early. I had stopped taking metformin, and my OB/GYN said I was right to stop taking it, but I have been reading a few studies that state how metformin can lower the chances of miscarriage in women suffering from PCOS... what do your Docs say??? I am curious to know :)

So, I was browsing some galleries on FF, and came across one with Positive Pregnancy Tests. I was fascinated at how some women start testing as early as 6DPO and sometimes even get a faint line! Of course, they continue testing on a daily basis (sometimes twice a day) to see if the line progressively gets darker. More women start to get a faint line starting 9DPO, and most can see positive results at 11DPO, and beyond. Obviously, this all depends on your own LP, but I can't help at wonder...

So the question remains... What is the earliest one should test? And which is the best test for detecting small traces of HCG? I know the lower the number, the easier it is for it to detect a tiny amount of the hormone... so what has been your "go-to" stick to pee on???

The last time I got my BFP, I am not sure how many DPO I was, since I wasn't temping... I was just going by my "regular" cycles at the time, which were 35 days (like clockwork). My Period Tracker App estimated that I Oed on day 22 of my cycle (read old post here), and we BDed on day 21, which was right around the time we were celebrating our Anniversary ;) Well, this time... I Oed on... CD22 - again! My first faint line appeared at 11DPO (and looking back, it wasn't THAT faint, especially after confirming some early results on FF), and my official digital reading appeared at 15DPO.

I don't think I can hold out until 11DPO this time :-/ I might want to start POAS at 6DPO, and I don't care if that means I have to buy more than one box of tests... Any thoughts?? The anxiety is KILLING me!!!! LOL LOL LOL!!!