In my 34 weeks, having on and off abdomen pain. Quite painful at times. Even when lying on the bed, changing of position doesn't help at all. Any idea what's happening? Should I call the hospital?

Are you experience pain on the right side of your rib cage? You may want to describe the sensation to your doctor. Abdominal pain is not normal at this stage and if what you are feeling is constant lower abdomen pain, find out what you have consumed before such as barley water, pineapple etc. You can consider seeking advise from TCM or Ayurveda Doctor if this is food related. Otherwise, please consult your doctor.