In the simplest terms of American freedoms, no pharmacist should, nor in fact can they be forced to sell the morning after pill. To do so violates the very principles this country is based on, not to mention the sanctity and necessity of observing religious beliefs in this country.
First and foremost, a pharmacy is a business. Now, in this country we have laws regulating what a business can and cannot sell, how they can sell it, and other sundry regulations generally meant to protect the populace. The government does not, as a rule, and should not ever; state that business MUST sell a product in order to conduct its business.
Such a law is protectionism for a product, and is acceptable only in the extreme cases required to break up monopolies that would have destroyed the markets and ruined free trade and capitalism as we know it today. To force a private company to offer a specific product, particularly one that is not a necessary medicine, as in this case, is idiocy and a violation of a businessman's rights as an American citizen.
Further, religious beliefs and practices are protected under American law so long as they are not a hazard to the general population. So if a Pharmacists wishes not to sell the morning after pill because he feels it violates his personal beliefs, so long as he is a private pharmacist and not one employed by the government, he has the right to refuse to stock the product.
It's that simple. Now people may argue that it is a service the public needs. It's not. People got along fine for centuries without the morning after pill. And odds are if one pharmacist isn't carrying it, that another, in the interest of good business, will carry it, and so take in all the profits that the competing pharmacist loses by honoring his religious belief. Supply and demand tells us that where there is a demand, someone will supply.
Therefore, there is no need to force pharmacists to sell the morning after pill. If one pharmacist won't, another will, and so the demand will be met. If this is an inconvenience to someone, because perhaps they have their prescriptions with the pharmacy not selling the morning after pill, then perhaps they should change pharmacies.
It's simple really. The government should never impose upon a private business what it must sell. A product is either legal for sale, or it isn't. If it is legal, then carrying that product is up to the private business. To force a business to carry product violates the founding principles of this country.