Hello,
For a reproductive age woman there is no normal thickness endometrial stripe. The thickness and sonographic characteristics of the stripe will depend upon the phase of the menstrual cycle. In a postmenopausal woman the endometrial stripe should be less than 5mm.
Whether fibroids impact infertility is questionable and when thought to do so it is usually when they are located partly or completely within the endometrium: what are called submucosal fibroids. You should ask your doctor about the location of your fibroids.
Most infertility is related to anovulation (irregular menstruation), male factor (abnormalities of a man's sperm), and tubal factor. If you have been trying to conceive unsuccessfully talk to your ob/gyn about undergoing the appropriate work up.
Best regards,
Dr. Downing
This is a forum on Ovarian Cancer, and as such, you will probably not find your answer here. You would probably have better luck if you asked your question in the Gynocology, Women's Health, or Pregnancy forums.
Good luck to you.
Gail