Not at all! You can purchase a subscription at any time. When you buy a subscription, your subscription is extended, not replaced so you can purchase now and not lose any time!
How do I purchase a MusicplayOnline subscription?
Check out this article to see the different ways to purchase a MusicplayOnline subscription.
Delaying/Pausing Subscriptions Purchased
There’s no way currently for us to delay a subscription to start in the future. As soon as a subscription is applied, it starts automatically.
Similarly, there isn’t a way for you to pause a subscription once it’s been applied (unless you are part of a district).