Is Ureaplasma Contagious?

Hello, I am a male and had tested positive for ureplasma after going to a urologist saying I had weird sensations in my urethra, but never experience pain or discharge. When I tried to ask my urologist for more information about it because I never heard of it before he was dismissive and said I was making a bigger deal out of it than I need to. He said it was an STD but when I asked if I should contact everyone I ve been with he said No. In his opinion, I only need to tell someone if I was currently having regular sex with them because then I would be at risk of being reinfected. When I also wanted to be re-tested after antibiotics he thought I was just being paranoid. I was wondering if he considers it an STD then why is he so non-chalant about it so I looked online and it appears that it s actually not an STD. But then online information also said it can lead to infertility and other things. Ultimately my questions now are: How serious/not serious is ureaplasma? And very specifically - Because I was tested for STD s that came back negative, my new partner and I felt it safe and had unprotected sex regularly for about a week. Due to distance we haven t had sex after that and currently not. However, I later discovered that I had ureaplasma at that time. Does she need to be informed and treated for it as well before we have sex again?