has my app subscription really been cancelled?

I accidentally subscribed for a 3 day free trial of an app, which after 3 days it will cost money yearly. I clicked cancel subscription in my settings, however the subscription profile is still there and it says the subscription is only cancelled for 3 days... I see no other way for me to cancel the yearly one. Does this mean I will be charged anyway after my free trial is up? Please help as I do not want to have to pay a huge amount of money for this app I did not even want a subscription with, thanks.