Re: Thick endometrial stripe?
21mm is a very thick endometrial stripe, indeed. Something unusual is going on and you should follow-up. A thickened endometrial lining that is still very thick on the day after your period ended means that there is overgrowth. There is a short list of reasons why this could be, some not bad at all, others more serious. A few minutes on the internet searching will give you plenty of possibilities, but I hope you will get more information from your doctor and lab testing to be sure you get some answers. Good luck!