i have always tested infp until three years ago it has been enfp .
i use varius online test, which may not be as accurate. one i can remember is human metrics .
I have changed as Ive grown older .. not as shy or introverted ....and other things.

www.humanmetrics.com/

As far as I understand it, I don't think we ever "change types."
Though I may have read somewhere that as we get older we focus on a diifferent "function of type," if you understand what that means.

My favorite two regular test are:
www.bbc.co.uk/science/hum.../index.shtml

4np.net/ddli/

And a good one to take (focusing on the functions of type) is:
www.cognitiveprocesses.com/asse....html

I have come out ENFP on tests recently but I believe that INFP is my true orientation. I was extremely shy as a kid, but not so much anymore. I actually do get energy from social situations, but I believe my cognitive process is still introverted. I am more focused on my own feelings and ideas then on the world of people and things. I think this is where some of the confusion in defining introversion vs. extroversion comes from; in whether it is defined in how you receive energy vs. in how your cognitive process works. Further confusing matters is that I have read descriptions of ENFPs that say they need a good deal of alone time compared to other extroverts! Ask your friends if they see you as an introvert or extrovert. Most of mine say introvert!