Is it three month free trial or one month?

Hello. I just subscribed to Apple Music seduced by the Three Month Free Trial offer but then after I subscribed I got this confirmation page that says that even though I have a 3 month free trial period, I will get charged after the first month. Eh? I am confused! Can somebody explain this? I signed for three free month. And i will not pay one dime until those three month end. If I don't get that, I will unsubsribe. Period. So please tell me I am reading this wrong. Thank you!