My boyfriends brother just found out his girlfriend is pregnant. My boyfriend commented on how he's been coming in me since February and nothing has happened and how we have sex more frequently. She's 17 and I'm 21, but I was on birth control for less than a month 10 months ago, and since then I've only had 2 periods and have gained a lot of weight very suddenly. It makes me feel like there's something wrong with me or that I'm no longer fertile