As for your wife...if she gets pregnant her breasts may increase, at least temporarily. If she breast feeds, same thing. If you fork over big bucks, she can get breast implants IF SHE WANTS THEM (this is surgery buddy; you don't get to decide for her if she goes under the knife). If she gains weight her breasts may increase in size.
Otherwise she is what she is. This is who you married.
You're 16, you're not married, you have no insurance, you have abnormal vaginal bleeding, you can't go to a physician...and you believe you're prepared to "be a mom"?
Take a step back, take a deep breath and put things in perspective. You need to get this abnormal bleeding looked into medically first. Is there a Planned Parenthood Organization where you live? They offer lower cost reproductive services and don't require that someone has insurance.