it really depends on they type of pill you are on Satchi. Dianette and Yasmin are similar pills and I think they are anti-androgen pills (I'm no chemist!) so they help regulate dodgy hormones that can cause acne. I don't think it caused any weight gain, and if it does its only 3 or 4 llbs - nothing that a healthy diet and exercise regime wouldn't wipe out in 2 weeks or less.
Go to your GP and ask about the best one for you, although if they do prescribe a contraceptive pill to control acne, make sure they put it down as a contraceptive - then you get it free (if you're in UK).
The main risk with the pill is deep vein thrombosis, but as long as you have a good blood pressure and your BMI is ok, then it should be fine!