Under 28 day mark! Marriage License time!

I would check with your city/state's website. Here is what ours says about it:

If you only want to change your surname, you can sign your marriage license with your new last name. This change will be reflected on your marriage certificate. You can then use the certificate as proof when you update your driver’s license, passport, and other documents.

If you want to make a more significant change, like shifting your current surname to your middle name, you need to file a petition with the Court of Common Pleas