Weight distribution re shoulder bags

I have taken to wearing a bag. On my shoulder, not my head.

I am wondering. If the strap is on my left shoulder and the bag is at my right hip. Which side is the weight on?

I feel the weight on my left shoulder (it get’s sore) but the mass is dangling away on the right.

If I have 10 kilos in the dangling satchel, on which arm should I hold my 10 kilo shopping basket to even things out?

Thank you.