Period or early miscarriage?

Am
I have been ttc #3 for 3 months. My cycles are 28 days with 3-4 days of bleeding, first two days are light to moderate and the last day or two is just spotting. This month however AF started two days early and was very heavy for about a day and a half along with bloating and mild cramps (which I never get) followed by 3 days of spotting and it's still continuing. 
Could this be an early miscarriage or just an odd period? I took a test this morning (day 5) and got a bfn. Any thoughts?