Personality Type

So I've gone from an INFP to an INFJ to an ISFJ now??? I don't understand. -___-; Though I took the test again with some choices I was iffy about and it goes back to INFJ . . . so I guess I'm pretty borderline on the N versus S, but I guess I'm well into the J camp now??? Huh.

Anybody else notice any changes in Personality Type over the years?

I took the test here, BTW.