Probably not. If the mucus is kind of sticky it would be the cevical plug. If it's not sticky and flows it would be the delivery lubricant fluid. If there is a lot of red, like fresh blood, then I would be concerned. If you have a neighbor, friend or vet handy that knows what they're doing you could have them sleeve up and check things out. Otherwise I wpuld leave her a lone and let nature take it's course. Has she had any signs of labor or impending delivery? Restless, seperating herslef from others, off feed, kind of mooing very softly, carrying her tail in the pump handle position, etc.? Those are are sme of the signs of impending delivery. She may have all or none of them, they're just general indicators of what to look for