Course of antibiotics can be given for 14 days based upon culture senstivity report but in case if symptoms persist may have to switch over to higher class of antibiotics.
You should have to care for perineal hygeine. Use some intimate wash for perineal hygeine, avoid using synthetic garments and take plenty of water orally. In case it still persists please feel free to have a gynaecoligist visit.
U have not mentioned about your symptoms. As report is more or less normal. But if you have symptoms then you need to take treatment for uti. 1.You should maintain high grade of personal hygiene. 2.Do change your underclothes at least 2 times a day
3.Wear cotton under garments
4.Stay hydrated. Drink plenty of fluids.
5.Keep the area dry
homeopathy is a very effective for this problem n has very encouraging results. And homeopathic medicines are safe and do not have any side effects at all.
Urine culture & sensitivity is done to check whether you have any urine infection, it also tells which drug is best for you if you have had an urine infection.
Since your report says “sterile” it is likely that you don’t have any urine infection.
For any other queries consult with me on my Lybrate profile: url/drchavankarthik.