Is it a false positive?

Miriam

I had a miscarriage back in July. The past couple of days I’ve been feeling off to the point it made me feel to take a pregnancy test. It came out positive but how would I know it’s not a false positive? The last appointment I had was mid August to be sure of where my HCG levels were. Of course I will call my doctor on Monday to know for sure but I’m so confused on how to feel about this positive test.