I went to the dr today and i was dilated to 3 and 70% effaced and now i'm having sharp back pains bad?

See your doctor: You have symptoms which could be serious and should see your physician. He/she will listen to you, do a physical examinarion, run some tests, and let you know what's going on.

Dilation & back pain: Your body is getting ready for labor. You're almost ready. If your water breaks go straight to your doctor's office or hospital. Otherwise wait for regular contractions. Good luck!