Did I break my own finger?!

Okay, so my ex bf and I were messing around after school. (not in a dirty way btw) He had taken my bag and hid it. So I grabbed his. He got a hold
of it and pulled with all of his strength. Well I went to the doctor and my finger is..... BROKEN! So I get back to school. And everyone is like, you broke your own finger, you broke your own finger. And it makes me so mad. But are they right?