I was texted positive for chlamydia and my partner tested negative how did i get it?! i've never been with anyone else

False negative: Or false positive. To be on the safe side, both people should be treated.

From your partner: You got it sexually from your partner. Assuming your test was not a false positive, your partner's test must have been either a false negative or an indication of disease latency or cure. It's not unusual for one partner's immune system to suppress/eradicate an infection better than the other partner, and there are differences between the sexes here too. Both of you should be treated to be sure.