What does an ultra sound that says normal uterus but very heterogeneous with a few poorly defined fibroids mean?

May mean adenomyosis: Difficult to say for sure. You should discuss findings with your doctor. I often see pelvic ultrasounds describe significant heterogeneity which is due to adenomyosis but called fibroids instead. They are both benign conditions and both cause similar symptoms (and you could even have both). A pelvic MRI is a good way to answer this but first talk to your doctor to explain the results.