utirus line is thick

this has happend to me twice already ! i have been trying to get preagnant for 4 years now , i have a history of endrometiosis but thank god i dont have any cycts its been 3 years they have been gone and til now i dont have them ...

so back to the utirus today its my 12th day and its really thick more than normal the first time it happend when there is 1 week left for my period and the doctor thought i might be preagnant but this time i am really worried guys the doctor didnt give a a full answer to why this is happening okay let me clear something my hermones level are perfect my ovarias are perfect as well because i recently tested them now has this happend to anyone here maybe i can have more information until my doctor speaks to other group of doctors and gets back to me so i have never had kids before i am 22 years old i have been trying to get prego for 4 years

thank you..