Possible miscarriage please help.

Hi

I switched to the pill. Missed it a few times. Had sex. I did pregnancy tests with cheap ones every now and then and they came back negative. Havent had a period for 52 days. Now I have intense bad cramps, feel sick and bleeding had clots and one big one that was white pink and reddish. I put a tampon and the blood was brown. After the clot a little while later the bleeding stopped. Is this a sign?