Lower back pain doesn't usually mean you're in actual labour but it means the baby is moving into the birth position, many woman feel lower back pain as this is happening. If it doesn't go away, it's most likely you'll go into labour very soon. So get prepared or seek guidance from your doctor.
I been having the same problam. I wouldnt think its labor. If your in labor you will know. But if your having back pain I would go get checked out by the doctor but the discharge could be your mocus plug