Hi cowsaregreat
Any change in application site may slightly affect the amount absorbed and whether you notice this or not will depend how sensitive you are to slight changes. You haven't said where you applied it before? Skin on the inner thigh is very thin so absorption should be good!
As long as application site remains consistent - ie you stay with that site - all should be well...
Yes probably overthinking - you would not experience painful hips soon after changing! Any effects like this from changing dose would take longer to be apparent....
Glad you're getting on well generally anyway

Hurdity x