it could be your ligaments stretching for the baby, i know its high up, but it could be pulling at the sides higher up for room for the baby, i had this when i was 14 weeks pregnant, right before i went to my first appointment with my family doctor, i was in the shower and started feeling dizzy, then when i got out i had to sit down, there was a pain at my sides, and i thought ill just stand up and stretch a little to see if it would help, i had to grip the side of my computer desk it was so painful, but then it went away.
I had alot of "night sickness" too, one time my fiance and i went to a movie and i had to rush to the bathroom and throw up. Another time we were out for dinner with friends and i had to go get sick.
Hopefully its nothing serious, but let your doctor know about what you felt the other night, he or she may have a better answer or guess of what it is