Help! Maxi dress crisis!!!?

My prom is tomorrow and I bought a maxi dress for it about 2 months ago. I never noticed at the time, but when I tried it on earlier today to see if my chosen hairstyle would look ok, i realised that it was really see through but only from the hips down. What shall I do?! If i wear leggings under it, would it be weird? My dress is blue btw. Please help, it's urgent! x