STD HELP!

I went to the hospital about a week ago due to extreme stomach pains, fever, sweating, vomiting, diarrhea, the whole works. While I was there it’s routine for them to take blood and urine samples. My urine sample cake back negative TWICE. Due to it coming out negative I had to have a pelvic exam just to make sure things were alright. The doctor said that nothing looked out of the ordinary. There was a little discharge but it was it was nothing I should be worried about. They took a culture to test me for STDs just in case. Test came back 2 days later and I’m positive for chlamydia... I’ve been with the same man for the past 3 years... I haven’t had sex with anyone but him and he hasn’t had sex with anyone but me. He went to the doctor to get checked out and his test came back negative... I’m not sure what this means.. Maybe I had a false positive? My boyfriend is iffy on wether or not I’ve actually been faithful but I know for a fact that I have been... I really need help and I’m not sure who to turn to now.