If you are lopsided - the lumpier side is usually all the limbs! When I was first learning about position, I thought that the bulkier side would be where the spine is but it is the opposite! If your belly is ovoid and not irregular, it is usually a good indication that your baby is posterior (ie spine against your spine)! It's pretty cool, don't you think, that the shape of your belly can go someway to knowing the position of your baby?!?!