I got treated chlamydia a while ago & realized i had it for about 3 or 4 months at most. having it that long, could it have caused infertility?

Possible but not : Likely. It usually takes a few months for complications to develop, but 3-4 months is long enough to cause damage. See this site for more info. http://www.mayoclinic.com/health/chlamydia/ds00173.

Possibly: Untreated chlamydia can lead to infection in the tubes and cause blockage. But this doesn't happen to everybody who has chlamydia so hopefully you weren't effected.