If i didn't seek medical attention for my uti but the symptoms are pretty much gone after a couple days, will it stil spread to my kidneys?

Probably not: Many people have UTI without symptoms. These do not need to be treated. People do clear UTI without intervention. If your symptoms resolve, the UTI may have cleared. However, there is a chance that an infection remains asymptomatic and can eventually worsen and cause worsening symptoms later and spread to the kidneys. As long as symptoms do not return, most likely, you will not have to worry.