Can Jelly-like Clump Discharge Be Bleeding Or Miscarriage?

I am on the pill and was supposed to be on a break about 2 weeks ago but i didnt take my break. So 4 days ago i took my break but i did not come on my period untill today. This morning i was having very bad stomach and back pains and as i was walking to work i felt as if i was bleeding so assumed it was my period. However, when i went to the toilet it was a jelly-like clump of flesh. It was like skin and could be stretched but did not break. I have hardly bled since this morning and am worried about it because i'm not sure if it just my lining or if it was a miscarriage?