Google Play library 3.0 check if user used introductory price

I am using Google Play Billing library 3.0.3 with Java. I have an introductory price on my subscriptions.

When the user already have used the introductory price, the getIntroductoryPrice() function from Google billing library still returns the introductory price.

How can I check if the user already used the introductory price for not showing it again to the user?

I want to show the introductory price just the first time, when the user have not yet used it.