Is it normal for slimmy stuff to come out of the vagina during a period? i'm not sexually active.

Probably: During the menstrual period you will pass blood, clot, tissue fragments, and mucous. Sometimes the entire endometrial lining will pass at one time - that is called an endometrial cast, and is not abnormal. What you describe is likely perfectly normal.

Yes: It is normal to have a variety of vaginal secretions during the month. Near the time of ovulation, those secretions become very slimy and stretchy.