What Causes White Fibrous Discharge From The Vagina While Suffering From Uterine Fibroid?

Hello, I have fibroids and heavy, clotting periods. I just passed some chunks of white fibrous tissue tinged with blood. Could this be the fibroids coming out? Have also had abnormal paps and biopsies that turned out ok about 6 months ago. Could this be something that got missed? Thank you.