My understanding (and I'm not a lawyer), it that the patent can be invalidated if it doesn't correctly list the inventors. Since it doesn't cost the company any more money to list you as an inventor, they really should if you indeed merit it.
That said, you need to determine if you actually are an inventor. Here is a scenario. Lets say that Mary has a great idea for a new widget. She sketches it up and her management decides to pursue it. Bob works for two weeks creating CAD models and then Sarah spends a month machining a prototype. Jack spends 2 months testing and characterizing the widget showing it works. A patent application is drafted and the patent attorneys decide that only Mary is the inventor because only she came up with the novel idea which is expressed in the claims. While the other contributed greatly to the success of the invention, they didn't actually invent anything.
So the bottom line is you need to look at the claims. Is there at least one claim where you were the one who came up with the novel or inventive step? If so, you need to be listed as an inventor on the application. Applications typically take 18 months to publish so you may not be able to see the application for a while. I would contact your former employer (perhaps you manager) and ask about the status of the application and whether you need to be included as one of the inventors. You can express concern that the patent be valid with respect to inventorship.
Although there really isn't anything you personally should worry about, I do think you should verify whether you should be listed as an inventor and if so make sure you are. Having a patent on your resume looks good and could help you while seeking future employment.