Miscarriage?

So obviously I’m going to see a dr but in the time being I wanted to ask on here.. I’ve been testing positive on ever pregnancy test but today I had some brown blood when I wiped, looked just like the beginning of my period. And ever since then I’ve been having extreme cramps. They’ve just been getting progressively worse. It started hurting so bad I had to take Tylenol. Am I definitely having a miscarriage or could this be something else?