What Could Menstrual Cramps With Fleshy Lumps Suggest?

i am on my period and this month i am having terrible cramps. i've just been to the bathroom and there was a strange skin like clot. its like a lump of flesh, a yellowish colour with a large blood clot at the other end. i squeezed it in the bathroom tissue and it popped. i looked it up online and other people who have had the same thing have suggested a miscarriage. i'm a bit scared. i've always used protection with my boyfriend. should i go to see the doctor?