I've never taken that particular type (my doctor put me on Yaz, then switched me to Ocella, the more generic version), but I wouldn't concern yourself too much about weight gain because of it...any time you introduce something new (particularly something meant to alter your hormonal balances), your body is liable to freak out a little bit and do silly things because of it. So long as you keep to a healthy diet and exercise, I'm sure that things will level off after a period of adjustment, and you may even find it easier to lose weight because your levels are closer to the norm.
In other words, don't worry too much about the number; worry about how you're feeling. There may be a transition period, but in the end the most important part is a healthier, less-pained you. Regardless of what you and your doctors decide, best of luck!