I'm 39 weeks pregnant dilated 3 cent. 80% effaced am having sharp twinges in my lower abdomen and pelvic area ?

Sounds to me like you may go into labor at any time. The stats you give, 3 cm, 80% effaced, when did you get that info? Those things can change quickly. And labor pains aren't always excruciatingly painful. With my twins, my contractions were fairly tolerable, and I had a very short, fast labor and delivery with them. Start timing the pains. Are you having contractions or just pains? If they continue, or increase in frequency, call your doctor, or just go to the hospital.