Does anyone know if those rubber sweat bands/belts that go around your midsection are safe to use during your first trimester? I've used them in the past (not pregnant) and was wondering if it would be a good idea to use them now before I get a "pooch" just to keep my stomach flatter for longer and to possibly get back in shape sooner after baby. My main concern is whether or not they would be safe? It makes your belly sweat more becasue it is made out of rubber. Thanks in advance.