You can update your Milestone week by adjusting your due date under User Settings > My Profile. 

Steps to Update Your Due Date

From the home screen, tap the hamburger menu (☰) in the top left corner. 

Scroll down and select User Settings. 

In the MY PROFILE section, tap manage my profile. 

Scroll down to the DUE DATE/DELIVERY DATE field. Tap the calendar icon to adjust your due date. 

Be sure to tap the SAVE PROFILE button to save your changes. 

Video Tutorial