Is Bleeding Sign Of Period Or Miscarriage After UPT Positive?

Every month my periods begin on the same date. The third of every month. Me and my husband have been trying to conceive for 6 months now. Last month my period was very irregular. It was more like mild spotting, the color was light brownish and light pinkish. I missed my period this month, and I took a home digital pregnancy test, and it said I was pregant. Today is the 6th and I have been bleeding really heavy all day long, as if I started my period. I have had 2 miscarriages in the past couple of years. I am 21 years old. Am I having a miscarriage now?