Possible uti. A&e?

[20YR 1ST BABY]

so last summer I had my first uti, I went to my des who tested urine and said there was no infection so figured I was just fluey with really bad aches. 3 days later I was in severe pain fever over 40 degrees and rushed to a&e and hospitalised for a week as it spread to my kidneys. I know being pregnant we are more prone to these and it can affect baby, sending you into Orem labour or low birth weights. Nhs website says if u can't see your gp right away go to a&e. Thoughts please?! Xx