If you do a Google search you'll find a business listing for a Widmore Pharmacy. The data sheet (the part you can access free-of-charge) says they're located at
195 Widmore Rd, Bromley, England
Their business info says:
Proprietary Stores
Line of business: Drug Stores And Proprietary Stores

Widmore is a section of the Borough of Bromley which is in London.

Might the preg test be one of Widmore Pharmacy's proprietary (marketed under their own name) products? If so, that might mean the origin of the preg test was in luggage of an English citizen on the flight.

Any UK residents on the board that recognize this as being a real product?

If it is a real product, then the significance of the preg test, if there is any, would probably lie in some other aspect of it, not its name. I would think the writers, producers, etc. would be running a risk to connect a real world business to the mythology of the show.

__________________
Things fall apart, the center cannot hold;
Mere anarchy is loosed upon the world,
The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned;

--Lines 2-6, "The Second Coming" by Wm. Butler Yeats