How long does it take for chlamydia to cause infertility, I have had it since august and it is now november?

Unpredictable. You are correct that chlamydia can cause infertility by scarring down the fallopian tubes. In most cases though it will not. Which cases will cause infertility and which will not is unpredictable. The key is to take care of yourself, get treated and protect yourself to avoid catching it again in the future.