I just joined, so sorry for just jumping in, Lol. Anyway, I read a few pages of this thread (definitely not all lol) and I don't know if it has been mentioned, but with the BOAS I think though it may work, I wouldn't put too much stock in an early negative. Reason being, the test is still only as sensitive as it is with urine. I mean, if the test detects 25miu for urine, you would still have to have 25miu in blood for it to show positive. From what I've seen on betabase, at 10dpo most will have less than 25. So BOAS may detect a little sooner than POAS, but I wouldn't think it would be by that much.......
And on that note, I am 7/8dpo today and tried the BOAS, Haha. Maybe had the faintest line, but almost positive I'm imagining it, Lol. I will be trying again tomorrow or Friday.