PLE-4491

A 23-year-old G1P0, who is in her 15th week of pregnancy, consulted due to fever and right flank pains. Her temperature is 38.9°C, blood pressure is 110/70, pulse rate is 85/min, respiratory rate is 20/min, and fetal heart tone is 137/min as detected by Doppler. The rest of the physical examination was essentially normal. What is the probable diagnosis?