Weight Gain Denial

i recently had my prenatal checkup and my doctor said that i already reached my weight gain limit. i couldn't believe it. i thought i had a couple of allowance left.
the allowable weight gain of a pregnant woman should be around 20-30lbs.
i'm blaming the hospital's weighing scale for this. my baseline was 120 lbs and now my weight (according to that *&$#@%!!! weighing scale) is 150lbs. NO...NO...NO....
i've been regularly weighing myself and the last time i checked, that was a week before my checkup, i was 136lbs. see, 14 lbs short from the maximun 30lbs limit.
i weighed myself again and again and again after the checkup and according to OUR ol' trusting weighing scale i weigh only 143lbs.
*gulp* 7 more pounds til my limit.