I wouldn't say you are being a worry wart, but at the same time I wouldn't be overly concerned. Your body will practice for labour with contractions that can often be painful at times. If it happens again try to lie down and rest and if the contractions continue when resting then let your midwife know.

Some time off work seems like a good idea too, Your body is growing a person, it's ok to slow down and concentrate on that.