Uriel Meditex Double Inguinal Groin Hernia Belt, Medium

I have a 31 inch waist and the small and medium sizes do not show this size. Will the small size be be the best fit in my case?

Can this belt be worn under underwear?

Can you remove one side of the pad to wear it just on the left and not a double?

Can I return this product if it is the wrong size?