Backaches are pains or strains that occur in your back. Most women notice this is in their lower back, but the pain can move upward.
What is the reason of this?
Most of these back pains are related to the weight of the fetus in the lower back. As the fetus grows, the extra weight on the front of the body is often too much for the lower back muscles to handle.
Tips
The most common treatments prescribed are belly straps, bracing your legs, and full body rest. If none of this helps, you can always ask your healthcare provider for its opinion on what might help relieve your discomfort. If the pain comes and goes every few minutes or persists and is severe, you should call your doctor as these may be signs of birth.

