“Abnormal urine results?”

A few weeks ago I was diagnosed with having a strep B UTI. This is my fourth strep B UTI in a year. I took antibiotics 3+ weeks ago and on day 9 of the course went to the hospital with what felt like heart issues. I had heart palpitations and my heart rate was at 135. When the hospital checked my blood my CRP was slightly elevated and my troponin levels were high. When they rechecked my troponin levels had dropped to normal. My bedside urine showed normal. Since then, I have purchased urinalysis strips and two weeks later, I'm getting odd readings that show leukocytes are there at certain times of the day but not at others. There is a trace of protein = 15, a high specific gravity of 1.030, and a small trace of blood (orange-colored result with 3 green specks). I've been drinking 8 glasses of water a day religiously and have been frequently urinating because of it. My menstrual cycle is late by 6 days. I've noticed the amount of sweat reduced.

My questions are:
1. What could cause test results on a urine strip to fluctuate throughout the day?
2. Are test strip results after the 2-minute mark valid? Are results meant to be read at the time marked on the strip and results showing after that invalid?
3. If I'm drinking enough fluids, could my missed menstrual cycle be causing the result of protein and high specific gravity? I have a tendency to gain five pounds in water weight at the time of my menstrual cycle.
4. What could be causing these results?