I have never regretted checking a cow out too early....But there are numerous times that I HAVE regretted waiting too long! Knowing when to assist a cow is something every person who has pregnant cows should know. Of course we have standard 'rules' that say if we haven't seen progress within an hour of the water bag or appearance of feet we need to assess the situation. But there are times where we don't know how long she's been calving, or where there are no obvious signs that she is calving. F