43 y.o, not menopausal, no hormones, irregular periods & heavy bleeding w/emb result: fragments of inactive endometrium, scant benign squamous epithelium, no evidence of hyperplasia or malignancy. is this an expected or normal finding? why inactive?

An "inactive" result from an endometrial biopsy, with no hx of menopausal symptoms, may simply reflect when in a particular cycle the biopsy was performed. If after a "heavy bleeding" episode, most of the endometrial lining may have been shed during the bleeding, and the resulting estrogen production has not yet made endometrial growth sufficient for the occasion.