The jury is out on whether the pill affects weight gain/loss -- there are just too many varieties of pills, dosages, and ways that it could interact with your body/metabolism.
Some docs suggest that the amount of estrogen in your pill could play a factor in weight - the lowest dosage available right now is I believe 10 mcg of estradiol. I'm not an MD, though, so it's definitely something to ask your doc about.
My OBGYN told me that obese/overweight women are often put on a higher dose of estradiol because of their weight. I'm on a fairly high dosage of estradiol myself now, and hope to get it lowered when I go for a checkup at the end of this month.
Female, 28 years old, 5'4 1/2" tall
Starting weight 1/4/11 = 215.2 lbs.
Weight 9/3/12 = 164.9 (net: -50.3 lbs.)
Current mini-goal: 160 lbs.
Next mini-goal: 150.2 lbs. <--- Official "Healthy BMI" weight
Estimated final goal: 130 lbs.
"You don't have to change your life today. You only need to change your day today."