Just to clear up the confusion:)
Generaly speaking Subway is your better option out of the major fast food stores to eat at.
All the salads and meats have a set shelf life and must be used with in that time, after which they are thrown out. These times allow a decent period of time the product is still good for but wont be used in.
All subway stores have a mini health inspector that visits one day a month to check how clean the store is, proper products etc. Every store must meet the high expectations on a monthly basis.
Meat products are fine to eat but must be served piping hot, just request they are heated longer than usual. Processed meats should be avoided during pregnancy (ham, turkey salami, beef) In small doses they should be fine though.
If you are not sure look at the product, if it doesnt look right dont eat it, simple. All the products are in front of you so you can make the decision for yourself. If the store looks dirty/dodgy then dont eat there, the same as anywhere else.
That should be all you need to know, i've worked at subway for over 6 years so i know what im talking about:). If in doubt ask the staff about the product and if your still not sure dont eat:)