Hello, and I hope I can answer your question. Your back pain may just be caused by the way the baby is positioned in your womb. Certain medications for back pain can be prescribed during pregnancy and I suggest you discuss that with your OB. Also if you have access to a maternity store, they sometimes sell support garments that help hold your belly up which can take pressure off your back. Putting a bag of hot water on your back can help relieve the pain and will not hurt the baby. Acetominophen or Paracetamol can be taken safely during pregnancy in the normal adult dose. I hope this advice was helpful, and that you feel better. Take care, Dr. Brown