My husband is 7 weeks pos op. He fast-walks 3 miles every morning and he said that he is not feeling any pain or warmth anywhere.
BUT, everybody needs different time for healing. Six weeks is really still very early in the recovery.
Maybe you can try gentle stretching before you start walking and also check if your shoes are in good shape. Add some fish oil and vit B12 as well as alpha lipoic acid to your supplements since they all have beneficial effects on nerves and nerve pain.