Hi I am 16 years old and for the past 3 or 4 weeks my stomach has been really big, way bigger than it ever has before. A couple weeks ago I used to be 140 lbs (I am 5'4") and now I am 155 lbs, that's the heaviest I have ever been in my entire life! I can barely fit into any of my pants anymore because my stomach is so big, and not only is my stomach growing but my breasts have been getting bigger and bigger too and now they won't fit into my swimsuit or any of my bras! My arms or legs haven't been getting any bigger, it's only my stomach and my chest. I know this sounds a lot like pregnancy, but I took a pregnancy test just yesterday and I have taken a pregnancy test before my last period and they both have said no. The last time I had sex was with my boyfriend during my last period, which was about a couple weeks ago (I will be getting my period again soon) I know that you can get really bloated and your breasts get swollen before your period, it has always happened to me before about a couple days before my period, but this has lasted for weeks and it has never been this extreme. What is really confusing is that I have not been eating differently at all either, I did not change my diet and have been eating the same for years and I have always maintained a stable weight. I am not doing anything different about exercising either, actually, I have been exercising for an hour 3 times a week lately too, so it can't be anything to do with not exercising. This weight gain has been so sudden, I have no idea what is causing this! Please help!!