Severe back pain during pregnancy, especially in the 17th week, is not uncommon. There are several things you can do to alleviate the pain and discomfort. Firstly, try practicing good posture by sitting up straight and avoiding slouching. Use a chair with proper lumbar support or consider using a pregnancy pillow for added comfort while sleeping. Applying heat or cold packs to the affected area can also help reduce inflammation and provide relief. Gentle exercises such as prenatal yoga or swimming can strengthen your core muscles and improve flexibility, which may help alleviate back pain. Additionally, consider wearing a maternity support belt to provide extra support for your growing belly and relieve pressure on your lower back. If the pain persists or worsens, it is important to consult with your healthcare provider for further evaluation and guidance tailored specifically to your situation.