What if Chlamydia treatment doesn't work?

I found out 4 weeks ago that I had contracted chlamydia from my partner and was given 1 dose of azithromycin.  But after a week I was still having symptoms (pelvic pain, burning during urination) and a new symptom of intense back pain.  I followed up with my dr. and she told me to take aleve for the back pain--that it was my arthritis acting up.  But a week later still my pelvic pain got worse again and so I was given another test to see if I still had chlamydia and if I had gonorrhea.  Only the chlamydia came back positive which she said was normal due to the fact that it had only been 3 weeks since treatment and there were probably dead bacteria still present.  She told to me take a 7 day treatment of doxycycline (1pill twice a day).  I've been on it for four days now and my pelvic pain seems to have intensified to the point where I am losing sleep.  Is is possible for both regimens of antibiotics to fail?  If so, is the next step IV antibiotics or is this just my body responding to the medicine?

[gracefromHHP]

are you male or female?

you would've tested negative for chlamydia with the 2nd testing. you didn't test + from dead cells.  

this much pain isn't a symptom of any std. I advise you to be seen today and seek out a 2nd opinion elsewhere. they should be thinking non-std related causes at this point.

grace