So confused

Jessica • Name is Jessica im 27 divorced mother of a 4 year old son and baby #2 on the way :)
At 34weeks I went into premature labor and stay two weeks in the hospital when I got to leave they said I was at 5cm's. This morning I thought my water broke so I came to l&d and they are saying I am contracting but I'm only 1 to 2 cms and water didn't break. So how can I go from 5 back to a 1or 2?????