waking up crying in sleep

The past 3 days my daughter has been up most of the night because she's teething. Tonight is the first night that she actually went to sleep but she keeps waking up out of her sleep crying real bad. kinda like if she was having a bad dream. when i pick her up she instantly lays her head on my shoulder and falls back to sleep, but still whimpers. Anyone know what could be wrong???? she doesn't have gas, and i checked her feet and hands to see if anything had been wrapped around them causing pain but nothing!