I had a BT after 10 days. I did a HPT after 8 days and got a very light positive line. That just messed with my head as I was then convinced it was another bio chem pg. After the BFP I did another HPT and it was still light but a little darker. My HCG was 107. I think you need pretty good numbers to get a dark line. I won't say don't do a HPT but sometimes it can make you feel worse.