Help! Possible miscarriage?

the only way to ask this is to get a little graphic and give TMI... sorry.... for me a normal menstrual cycle is 28 days (exactly a month from the first day of the last period) and lasts five days, with spotting on the first day and cramps non stop on the second day that gradually get worse throughout the day then fading away by bedtime. between my last cycle and now, i have had some pregnancy symptoms. i took 2 HPT both turned out negative but at first a real faded line did appear then disappeared on both as quick as it showed. the day of my expected period, it didn't come. the next day had very little pink/brown spotting that would come and go. this took place for 2 days which is not my norm. on the 3rd day i started to bleed heavier, started to have bad cramps that would come and go in my lower abdomen and lower back, and then i past a clot about the size of a dime. it was real dark red almost black in color with a lighter red fleshy like thing attached to it. (not at all like a normal clot, it wasn't goo like or make any jello like movements, it was more or less solid.) since then bleeding has been mucus like and not real heavy, cramps have pretty much gone away. is it possible that i experienced a miscarriage? is it possible to know if you miscarried that early? has anyone else experienced this and was it a miscarriage or strange cycle?