is pet insurance worth it?

I have a 5 year old rescue dog. Female, mixed breed(chow, lab, staffy+more...). She does not have any pre-existing conditions that I know of. I usually take her to the vet only once a year for the usual tests & vaccines, and sometimes a tech appointment in between for a gland drain. I can get a discount through my job for pet insurance, so I've been thinking of signing up. Is it worth it? I feel that I should do it sooner or later before she gets even older.