After miscarriage Pg confusion

Beckie

I had miscarriage 15th sep. I had bloods done 2nd and 4th Oct they went from 55 to 30, we were told we could start to try again. I did a Pg test a few days later using a cheap and it was negative.

Ive done a frer today and there's a vfl, I got all excited, but then people said it could be from old pg still as it's a different test? What do you think?