As your womb grows larger, these ligaments stretch, and you can feel this in the groin area of the left or right leg. The ligaments supporting your womb pass through your groin and are connected to the pubic bone. This keeps the womb in a stable position.
By sleeping on your side with the leg that hurts on the bottom, the ligaments will relax and the pain will decreases.
Though you will have to put up with a certain amount of pain, it is also important that you try to maintain a properly balanced diet, and take particular care to get enough calcium.