Your home has a practical design load of approximately 60 pounds of
"live load" per square foot.
"Live load" means the total weight of the things in the room (bed,
people, furniture, etc.). "Dead load" is the weight of the materials
that comprise the floor itself (joists, plywood sub-floor, carpet,
etc.)

If your bedroom is 10 x 12 or 120 square feet, an acceptable live load
at 60 pounds per square foot equals 120 pounds times 60, or 7,200
pounds.

If you have a waterbed in the room, you should be concerned. Otherwise
it sounds to me like you're fine.

If you are concerned that you may be overloading the floor, you can:

Lay the wonderboard sheets flat on the floor (spreads and distributes
weight)
Take the smaller, heavier items and put them in another place.

Determine which way the floor joists run, then stack the wonderboard
sheets against the wall that is perpendicular (90 degrees) to the way
the joists run (distributes weight).

Or finally, why wait? Get busy and get the stuff installed!!! lol

Hope that helps!

Robb B.
Builder & Remodeler
Grand Rapids, MI