Endometrial thickness 26mm

Hello, I am new here and would just like a bit of advice. I have been told I have endometrial thickness 26 mm and am required to have a hysteroscopy for a biopsy. I have researched 26 mm thickness however have not found anyone as of yet to have such a high measurement, has anyone on here had the same as me or is this most likely to be abnormal. Thank you in advance.