How worried should I be?

My wife is 31 weeks pregnant with our first child and the doctor told her she was carrying the baby low. She examined her and said she could feel the baby's head. Then she took a sample and said she was going to see "If labor has begun", and asked for her to come back next week, and to take it easy and drink lots of water. She tested her for contractions and she said she wasn't having any but if she felt any cramping or anything to come and see her right away. My wife has had a little cramping, like once or twice in the past 2 weeks. Should I be very worried here? I'm asking this because i don't want to act worried and scare my wife any more then she already is I want her to stay calm.