Regardless of what people say about HPTs I think the majority of them are fairly accurate in showing a getting darker line or a getting fainter line. The fact that your POAS is getting darker is reassuring that your HCG is rising.
As for the bleeding no one wants to see blood when they are pregnant but its not always a sign of bad things and many people do bleed.
I think the BT results will be the best thing to give you an idea of whats happening.
Did you have repeat HCG test after your m/c?
My bleeding sounded similar to yours when I had what I was told was a m/c. It wasn't like a period, very mucousy pink/blood stained and I had tissue bits but not much blood. This went on for 8days. Turns out I had an ectopic pregnancy. I think people who have threatened miscarriages it often is mucousy so the fact its not like a period is a good sign. Is there any pain associated with the bleeding?