What are the signs of miscarage?

Okay, So I am 16 years old, and that sounds awful, but I had been with my boyfriend a year befor we did anything, which was four weeks ago. Since about a week ago, I have been feeling really sick and hungry. Yesterday I got sharp pains in my stomach and when I went to the loo, there was slight bleeding and a lump of something that looked like skin. Is it possible this was an early misscarage? Am freaking out a bit, deffinatily not one for the parents. I need to know, so that i can deal with it if it wasn't. :/

Thank you. x