Confused- positive then negative?

sa

Hi everyone. So I did a pg test last night (strip test)

as pictured and the line came up straight away. I decided to do another one with my FMU and it’s now completely negative not even faint. Just done another (first response pictured) and still completely negative. Has this happened to anyone else and all been ok? I’m not due AF until Friday but

I’ve recently had 2 miscarriages so I’m starting to panic a bit. Thank you in advance.