What Causes Pain In Pelvic Area And White Vaginal Discharge During Sex?

I have been experiencing really bad stabbing pains in pelvic area, this happens during sexually intercourse, passing urine or sometimes I just comes on its own. Also I've had a swear down for sexually transmitted infections and I don't have anything but I have a thick white discharge during sex and even in my underwear at times, please help I don't know what to do, this has only accured over the last 2 years since I had chlamydia, I'm 19 yours old and really worried