I would go and get it checkout just incase, it may be a small leak, the membranes can actually repair them selves and reseal, but JIC I would get checked out.

It may even be just excess mucus that is a little watery, but I think it would be safer to see your OB and get checked rather then leaving it and not knowing. I would prefer to go and be sent home and told it is nothing then sitting at home wondering..... peace of mind