What Causes Pulsating Pain Radiating Around The Back?

31 yr old female (5 weeks Pregnant), pulsating pain in LUQ, radiates around to backside, feeling of fullness and extreme bloating. Hurts more to lie down, pain mildly relieved when in fetal position. Causes dizziness and feeling of fainting. I have these symptoms intermittently for over 15 years and told it was IBS, spastic colon, and "Nothing" to worry about...please advise as it is not a comfortable way to live!