BLOATED OR NOT?? HELP PLEASE!!!!?

When you are bloated, when you lye down on your back does your stomach get flat or can you still tell you are bloated? I never really paid that much attention to my stomach so I dont know if I am bloated or if that is how it always looks, but when I lye down it looks normal. This is the week before my period but I have never noticed myself being bloated the week before, so its just weird for me. HELP!