How likely and common are false negatives?

Ive been testing for a month, all negative. I’m worried i’ll miss my next period as well in a few days. How likely is it that the negatives are false?

I know testing for a month is more than enough to know if I’m pregnant or not, but I have bad anxiety and the fact that my period is late by a month is scaring me.

I’m always bloated and have cramps, but no period.