Gaining weight

Im gaining a pound every few days. All of a sudden at 17 weeks i feel the need to always be snacking/eating and I follow my cravings. If I dont eat then my body starts to fuss as in nausea, gas, or lack of energy, even shaking. I dont know whats a good limit or what is enough because my body keeps asking (and im typically someone who snacks here and there and eats healthy and hearty) and if i dont do what it asks then i get hunger symptoms - but im also gaining some weight. Anyone else would say "oh thats nothing!" But i notice it. Anyone else the same?