What Are The Symptoms Of Miscarriage?

Hello ~ I have a few questions on miscarriage symptoms. I have never been able to get pregnant, but this month was wondering if maybe I had a miscarriage. My cycles have always been very regular, every 27-29 days, lasting 4-5 days, pretty heavy cramping the first and second day and medium to heavy flow. THis month I started my cycle on the 22 day with alittle bleeding and no cramping at all. The 23 day I passed 2 large clots, 24th day, another clot passed and still no cramping. I am now on the 27th day, with the flow being much heavier than it was on the 22 and the cramps have increased in the last 2 days. I'm just very curious.... thanks for your help!