1. Serum creat can be above normal by a small margin in few patients who are very muscular, heavy built, on high protein diet etc. However, to say normal, urine and ultrasound should be normal too.
2. Yes, creat can increase in presence of stones, specially if it causes blockage or infection
3. Yes. If the stone is non obstructive and single, most often creat will be normal.
Next Steps
If you have stones, you should consult a nephrologist and do all tests as advised.