lower left abdominal pain

I'm having pain in the area of the photo, not back pain but lower left abdominal. it's a dull achey pain, kind of like a pulled muscle not so much like a cramp. it hurts to move but doesn't bother me nearly as much when I'm laying down, the area isn't tender to touch. any suggestions on what could be going on? Just growing pains? I'm 18 weeks