Help, 10mth old crying all the time?

I have a 10 mth old who is generally always smiley and happy. She would sleep through the whole night. She has her two top and bottom teeth. The two teeth next to those, also on the top and bottom are coming out. The last two nights, she would not sleep. Tossing and turning, crying. She is not hungry, no diaper problem, wont take anything. Even when she sleeps next to me, she is rolling on her belly, then on her side, I dont get it. Why isnt she sleeping?