chalkboard tracker

Hi everyone! After battling infertility we got our beautiful blessing and are pregnant with twins! We just found out yesterday at our first 5 week ultrasound! I would like to do a weekly chalkboard update and don't know where to start. Has anyone found a good one or know how to create one? Thanks in advance and congrats to all the new mom's to be out there! We are due Aug, 2017! Here's a pic of our twinks!