No AF No BFP-- not sure what to think

May 20th- first day last period
June 23rd- BFP 
July 27th- first ultrasound, no heartbeat, rescheduled for a week later 
August 3rd- confirmed miscarriage 
August 6th- D&C 
August 11th- bled for 24 hrs 
August 12th- had sex for the first time since D&C 
August 13-28th- had sex 
August 28th- sharp pain in abdomen two inches two the right of belly button, lasted less then 24 hours 
September 3rd- BFN 
September 10-12th BFN 
September 13th- PMS type cramps no flow. 
September 14th- 2am wiped after pee one dark brown spot. 
September 15th today. Still no period. 
2 more days until 6 weeks post D&C. 
I'm afraid to take another HPT. I've taken 5 and all BFN. Dollar tree and FRER. I've had cramps, nausea only after eating and late afternoon but it comes in waves and goes away quickly, dizzy spells, stomach feels bloated but doesn't look it. Loss of appetite and headaches. I think if I don't get AF by the 6 week mark I will call my doctor but no more POAS for me. It breaks my heart seeing a BFN over and over again and still no AF. Thoughts or suggestions are welcome.