8 DPO after trigger when do I test?

I'm worried about taking a hpt after having my trigger shot on 08/23. I've read that after 12 days the HCG hormone is out of your system but I'm afraid I'll get a false positive and get my hopes up! If I take one 12 days after the shot that would be this Friday 09/04 and I have my blood test for pregnancy on 09/09. Should I test or just wait??! 😩  If someone could please give me some feed back I'd appreciate it!