14dpo & a possible VVFL?! whyyy

Courtney • 28 | happily married • 5 Clomid rounds❌ • Uterine Septum Surgery • 2 Letrozole Rounds❌• Natural BFP ended in an early MC😔
Took this with FMU. I then took a dollar store cheapie and NOTHING came up; BFN!
Do FR give off evaps??