Did I really gain weight ? :)

Few weeks ago, I checked my weight at a friend's place in her basement. I weighed 4lbs more than my usual weight. I just couldnt believe my eyes.. I was sooo happpy :). I weighed myself again at another friend's place a week ago.. I had gained another 5 lbs.. I was thinking this is ridiculous. Just two days ago, I read that a bathroom scale should be placed on a hard floor to get your correct weight. When placed on carpet, it has upto +10% error. So, I verified my weight again at another friend's place yesterday on hardfloor on a scale I've consistently used for the past one year. Verdict .. I weigh 4lbs more than my weight 2 months ago...7lbs more than what I weighed 5 months ago. I cant be happier :).