How to check if an AudioClip has looped?

Hi our group is developing a infinity runner game for smartphone and i work with the audio. I have a song that plays during gameplay that loops through out. However i want the song to change everytime it loops and plays over by changing the pitch and etc.

How do i check if my AudioClip has looped? I dont need help with how to change the audio file but what if statement to use to see if my AudioClip has looped if its possible