WEIGHT GAIN!! Holy Cow!... I've weighed 115 lbs for the last 4 ye...

WEIGHT GAIN!! Holy Cow!... I've weighed 115 lbs for the last 4 years of my life. I started on this new pill last week and in the past WEEK that I have i gained 6 lbs!!! It's not like I changed my lifestyle or decided to become a fast food junkie either. All factors are constant. I went to the gym today and I when I stepped on the scale I almost had a heart attack. I noticed I was bloated and everything was fitting tighter ( I just thought my fiance did laundry again and shrunk everything ). Has anyone else had weight gain from this pill? I have been on other pills, Yasmin, Alese, etc in the past and this never ever happened. Will this go away after the first month??