What happens if i stop the pill after only 7 days?

I was iffy about going on the pill anyway. I'm with a guy but am happy to use condoms and this pill - yasmin - is making me moody, have headaches, fatigue, etc. My doc said she wouldn't change the pill because it will help me with my skin - i have acne. I just want to stop now and move on with life. But my big question is - what happens? How terribly will it screw up my cycle?