Whether the endometrium is 6 mm after ovulation is normal depends on the specific situation. Normally, after ovulation, the endometrium becomes thicker, reaching about 6mm. However, this does not mean that this is normal, as in some cases this may be seen as unusually thick or thin.

However, if you're just curious, you can watch your own endometrial thickness on a daily basis. After ovulation, if you find that your endometrium is only about 6mm, you may want to consider consulting a doctor.

The thickness of the uterine lining varies from person to person, so if your uterine lining is only around 6mm, you may want to consider talking to your doctor. They can conduct a detailed inspection for you and give you reasonable suggestions. If you're not sure whether it's normal, you can talk to your doctor or a professional fertility consultant.