Chlamydia

I have had a long history of UTIs, I have been tested back and forth - also came back negative for Chlamydia 3 years ago.
Now I am with a new boyfriend (and of course we've had ourselves tested as far as HIV was concerned), and after severe pain I was tested positive for Chlamydia. We both took Doxycycline, but only after consulting the internet did I learn that it was actually a STD!
My question is now the following: has anybody had any experience with this disease? Is it really possible to carry the bacteria without having any symptoms? Is it sure that I got it from him, or is there any other way to catch the bacteria?
Any help, tips, suggestions would be greatly apprechiated!
With many thanks,
Sophie