when you go for your fitting, ask them to check for a leg length discrepancy. I have a 3 cm LLD that caused me a lot of pain until I got a custom crank set that corrected it. One way to check, is ask them to measure the angle your femur and tibia make relative to each other at the bottom of the pedal stroke, on BOTH legs. If they are significantly different, that can indicate an LLD. So can a different KOP from the right leg to left. If you have a small LLD, cleat shims may help.