Re: Could my girlfriend be pregnant?
All of those things you listed are symptoms from being on the pill. Weight gain, breast soreness, stomach problems, spotting, all of it. I'm sure she is not pregnant.
Jus tell her to make sure to always take the pill on time every day. And since you're not married, you should always use a condom. Besides an added layer of protection against pregnancy (which you need at your age), it helps against std's. It's not worth it for you to go without a condom, you're not ready to be parents yet. Her being on the pill and you wearing a condom is the best way for you both to be as protected as possible.