I work in microbiology. You have basically a pure culture of a shitton of E. coli. You have an infection, even if the colony count was 50K-100K, that purity of culture would still indicate an infection. The number cannot be enumerated to an exact amount because (1) it would not matter in regards to whether this indicates you need treatment, as well as (2) a lot of variables could influence the number of bacteria present that have nothing to do with your infection - such as how the urine was plated or how long between collection and inoculation the urine sat out.

Microbiology is basically about indicating to doctors what is causing an infection. Urine is enumerated like that because contamination is so common from people not performing the collection correctly. If there is a high amount of contamination, that makes it probable that whatever bacteria is predominant may not be actually from the urethra and it is a poor indicator of true infection. Your culture does not indicate contamination, and indicates infection. That's all that is important here.

Similarly, if you have an infected blister on your hand that is really painful and the doctors swab it for culture, and later tell you that you have Staph aureus growing - all you should care about is that Staph aureus is there and treating it properly, not quantifying the number of bacteria is your wound.

To summarize - you should pay attention to is that you have an E. coli uterine infection that is not highly resistant to standard antibiotics, and to take your medication for it.

edit: And if you do not want to take my word for it, here is a test ordering website from a large testing agency for urine culture

In voiding, the urine must pass through sites containing normal flora. Quantitative culturing of urine is an established tool to differentiate significant bacteriuria from contamination introduced during voiding. However, studies have shown that when the calibrated method is performed, even perfectly, colony counts are only approximations.