DULUTH (AP) - A Duluth woman training for a half-marathon says she thought she had pulled a muscle or ruptured a disc in her back before she ended up in a hospital emergency room.

And, when doctors told her that her pain was actually due to an impending birth, Trish Staine says she was in denial.

Staine says she told doctors a baby was impossible. Her husband, John, had a vasectomy and there were no signs of pregnancy - no weight gain and no feeling of fetal movement.

Staine says she ran for two hours Sunday and later had a sore back. On Monday, the pain became unbearable. An ambulance rushed her to a Duluth hospital where she and her husband were stunned by the news. The new mother says they've named their baby girl Mira, which is short for Miracle.