Miscarriage???

I am bleeding like a normal period and have bad cramping today but it's only been 13 days since I started my last period. My cycle is 25-26 days every month so I'm confused. I have been TTC for 2 months but no positive pregnancy tests. I'm wondering if it may be a miscarriage even though no positive results? Or my period all of a sudden is out of wack? Any insight or similar experiences? Thx!