What Causes Bleeding With Thick Pieces Of Tissue And Abdominal Pain?

I woke up in the early hours of this morning with excessive abdomen pains, not like any regular period pain. It took some time, but eventually these pains were relieved by Ibuprofen only enough to help me get back to sleep.



Later today my period started, and I am finding really thick pieces of tissue in the waste. The pains are ongoing and not letting up at all.



Does this sound like anything to worry about?



Many thanks.