Yes, I wear it everyday during my pregnancies. (Well, almost everyday.)
My mother (a Catholic) had a miscarriage (years ago obviously) and her mother (a Lutheran) bought the miraculous medal and gave it to her, telling her it was a “mother’s medal” and that she should wear it while pregnant. It’s become a tradition that the pregnant ladies in our family wear it, so it’s now my turn (my mom and aunts have passed it back and forth over the years).
Obviously we know it’s not a magic charm or anything, but a devotion to Mary asking her protection over our unborn children.
(When I’m not pregnant I wear it here and there throughout the year as well, but not daily.)