How long does it take a woman to become infertile when having endometriosis or is it quick?

This varies. This is a very individualized question. Endometriosis is definately associated with infertility. But it is unclear what degree of it is needed to impair fertility. Some women have very mild implants of endometriosis yet cannot conceive. If you were diagnosed with the condition, it does not mean you are fated not to concieve. It is a long process of evaluation and follow up. Just stay encouraged.