What is up with my girlfriend? (PLEASE HELP!!)?

My girlfriend is 18, I'm 16. Her lower stomach has been hurting for a week. In the daytime it hurts, in the mornings and at nights she feels sick, I have felt it at night and it bubbles inside her. She doesn't eat very well and she is very petit, we have had sex but she's on the pill. She's seeing the doctor next week, can someone help please I want my mind put to rest