Don't be ashamed! I have it also. There's more than one kind of chlamydia and it's as easy to catch as breathing! Some researchers also believe it's possibly a "gateway" infection that opens the immune system to all the other nasties.
"The Chlamydia pneumoniae (C. pneumoniae) organism, first described in 1988, is not the sexually-transmitted type. It is an airborne organism that you get from breathing after a person carrying the organism has coughed."
"They float around as droplet nuclei, similar to TB. People cough and up come these infectious bodies. They float around a room. You breathe. In they come and now you've got your own." http://www.mc.vanderbilt.edu/reporter/index.html?ID=779
Here's a very informational site that also explains how a regular course of Antibiotics only kills it in one stage of it's life cycle: http://www.cpnhelp.org/