No. A chlamydia infection from years ago would not cause an abnormal Pap test now. Most often an abnormal Pap test is caused from HPV (human papillomavirus infection) which is a sexually transmitted infection. There are over 100 different types of HPV. Your body can clear some of the viruses but other types can stay in the body for years causing changes to the cells on your cervix. Some types if left untreated, can even cause cervical cancer. However, you can lower your chance of getting HPV by getting the HPV vaccine, practicing safe sex (using condoms EVERY time you have sex), and either quit smoking or don’t start.
Information about HPV: http://youngwomenshealth.org/2012/07/05/hpv/
Information about the HPV vaccine: http://youngwomenshealth.org/2012/07/03/hpv-vaccine/