Hi, I'm 6 Months Pregnant And Had Some Discomfort, Got

Hi, I'm 6 months pregnant and had some discomfort, got it checked and had 20-25 pus cells, had hvs also done, which turned out negative. Later my doctor gave me suprax400 and asked me to take urine culture, which report says, no significant growth. What does this indicate? Why were pus cells present then?