I am 10 DPO. I still have a nice solid line when I take a HPT. I am still pregnant.
I am also, right now, spotting. It is brownish blood, only visible when I wipe. I am also cramping, just a little, they are slightly dullish, washed out cramps that are smack in the middle of my uterus. All of this of course can signify everything from normal to the specter of doom.
When you google "early pregnancy brown spotting" you will get a million hits. Such spotting is attributable to everything from your hormones (normal), to implantation bleeding (rare but normal), to the precurser of a miscarriage or ectopic pregnancy (specter of doom). And this is why the internet can be a terrible thing. For every "I spotted my whole first trimester and my beautiful little girl is sitting on my lap as I type this now" you can read there is also an "I spotted and it resulted in a miscarriage" or worse, "I spotted and it resulted in the loss of one of my tubes" anecdote.
There is a silver lining - albeit a twisted silver lining - in this development. If this turns out to be a chemical pregnancy, this would by far be the "easiest" loss I will ever endure. No surgeries. No protracted waiting. I am all of three weeks pregnant, there's not a whole lot in there. This little cluster of cells will go gentle into that good night.* I will dutifully return to my regimen of supplements, to hopefully avoid the loss of cluster #5.
*I love me some Dylan Thomas.