Am I pregnant?

I only had unprotected sex a week ago but I've been worrying ever since so today I thought lets do a test, I know it is going to be negative but maybe it would put my mind at rest. I've had tender breasts all day and can't stop eating. I am only 14 years old. I did a test and there was a very prominent line and a faint one. Does that mean I am pregnant? HELP!!!