Its very normal to discharge and cramp. When were you supposed to start? If you just ended your period just a week or so ago it's probably because your body is releasing eggs. That would be the reason for the discharge and slight cramping.

Just because your friends belly hurts and she's mean to everyone does not mean she is pregnant. She's probably suffering from either a bad day or what we all know as pms. Stress can result in an upset stomach. But if she's worried it is best to take a test when she is 4-5 days late with her period.