I need some information on swimming?

I am thinking about joining the swim academy at my high school for freshman year. In academy they teach you how to play the sport, and that will be beneficial considering I know practically nothing about it and I can't swim all that great. But the only thing is I am concerned on how it will impact my thighs and shoulders.. I mean I know its excersize and its one of the best excersizes you can do, but I already have somewhat large thighs and broad shoulders, its not really muscle, I just have a higher body fat percentage. around 32%.. I know thats pretty bad. and I dont want to make my body look all weird(i get very self concious about my body), I am a pretty slim person if it weren't for my body fat, Last year I had about 12% body fat and I was a size 0, now I am a size 7!!!. I gained alot of weight, so do you think that once I lose all the weight that I will have a slim swimmers body or a bulky one. because I know that some people have slim, and some are really bulky, and I dont want to be bulky. And I hear that they also have like no boobs as well. I don't really find that feminine, I dont want to look like a man!!! Please help!! I have about 30 days to decide what I want to do and I am getting all confused about the pros and cons, and what if I dont even like it......its pretty stressful for me..