Just got billed for personal premium, want to upgrade to family premium. How's it gonna work?

[raisarft]

I just got billed for Spotify Premium three days ago, and I want to upgrade to Premium for Family. How's the billing gonna work if I upgrade it today?

Will the family package start the next time I get billed, and the bill will change next month? Will the family package start right today, and I get billed twice this month? Or will it just start today and the bill changes next month?

Thank you in advance! Sorry if my question is not worded so well.