I'm sorry for your loss. And yes, it is true that you're more fertile after a loss. If I were you I would wait two or three days and test again. Make sure you use first morning urine. Best of luck with any future pregnancies. (:
I'm sorry for your loss... and I believe it is true that you're extra fertile after, I miscarried last year, had a d&c on Nov 2nd and then conceived Dec 12th, I am now 20 weeks pregnant. I'm not sure about the chemical pregnancy, I lost mine at 12 weeks. Your hcg may not be high enough for the HPT to pick up, or your period may be slacking... I would wait a few more days, possibly even a week and then take another test. Good luck!