What is a normal uterine lining thickness before my period?

Average is 10.5-11 . mm in mid-luteal phase and one of the studies showed that it does not influenced by whether there was a pregnancy or not after that cycle. If there is no specific complaint or problem, numbers can deviate and it can still be normal.
8 to 10 mm. The endometrial stripe will usually grow to a combined thickness of 8 mm to 10 mm in a normal monthly cycle. Some slight variation in this thickness would not be uncommon.