Definitely make sure you rule out pregnancy, although if you had a full period, its doubtful. Getting your thyroid checked is also a good idea as this sounds like a hormonal issue.

When you eat, what kind of food are you eating? Are you really physically hungry or is it just more of an uncontrollable urge to eat? Eating so much could be stretching your stomach and your body tends to adjust to your caloric intake, so if its used to getting that many calories every day for a few weeks straight it could be that. Especially if you are eating a lot of sugar, sugar is a hardcore appetite stimulant.

The pill can be a hardcore appetite stimulant too. The idea that the pill makes you gain weight itself is not really true, but because the pill tricks your body into thinking its pregnant, it can cause you to crave food much more than you normally would, which causes you to gain weight. I quit the pill a month ago and have lost 10 pounds, simply because I don’t have the urge to eat ALL THE TIME that I used to have when I was on it.