That's /MARGARET Kathryn Mumbledy/, goofball! (Keep it formal, y'know).
Like RKS said, you file in foreign countries when it's worth it to you to pay that price (cost of getting/keeping the foreign patents) to try to help keep the competitors in those foreign countries from copying your invention in those countries. Or sometimes you get started on paying those costs if you think it'll be worth it to someone ELSE.
Most companies file their inventions as a PCT application within 1 year after filing their first application filing, and the PCT claims "priority" to that initial filing. The PCT filing becomes a holding house from which you can file most countries of interest within another 18 month period (notable exceptions are a few countries who have NOT signed onto the PCT processing such as Taiwan, Argentina... can't remember others). Anyway, most countries are covered by the PCT. So you might consider filing the PCT application if you think you'll eventually be able to sell your patent application to a corporation. If they think there's any worth in controlling your patent application, it'll be worth more to them if they have foreign filing options.
PS, go also with RKS's reco on the Cute PDF converter (that's the "brand" name for the PDF maker that the USPTO refers to as ABXPDF). Even with complex chemical formulae that {High-Cost Brand Name PDF Software} sometimes fails to convert, Cute PDF works faithfully and well. (I miss it - my current corp won't let me put it on my work computer and insists on paying the licensing fees for that {High-Cost Brand Name PDF Software} which DOES occasionally fail to convert certain types of text such as the afore-mentioned chemical formulae faithfully).
EDIT: I just realized you're filing a US utility and claiming priority from a previously-filed US provisional? Your time to file the PCT expires at the same time as your US provisional (tomorrow, is it?), if you want to claim priority to the provisional.