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?

It could be Braxton Hicks contractions.. they can begin as early as the second trimester are most commonly experienced in the third trimester. Are the muscles of your uterus tightening for approximately 30 to 60 seconds, and sometimes as long as two minutes? If the pain increases in intensity and frequency, you might want to call your doctor right away.