7.5mg of letrozole and hcg shot

Lauren
Hi ladies .
 I'm 7dpo and had my hcg shot on 14th Dec. Has anyone had there BFP after their first attempt at this?? Also when do you think I should  do a HPT ? I've had feeling in lower abdominal and lower back pain for past few days. But I don't think I am thinking to much into it as I want it so bad. 
Merry Christmas & Baby dust to all you ladies🎄✨✨