Boyfriens tested positive for gonherrea

So my bf had pain when peeing and swelling down there. It lasted for 5 days or so till he couldn't take it anymore. We went to ER to diagnose what we thought would b a UTI. Turns out he has gonerrhea! We have been dating a short time(little over a month). Prior to me he had sex over a yr ago. Had a bad break up and just stayed to himself. I broke up with my ex 5 months ago. He was clean and I was too. So how did we get this? Im not dumb but if we are both clean then how did he get it? I am going to dr tomorrow and really hope i test negative. I have not had one symptom!!!