...is tomorrow, April 24.
The official website has information on the day, T-shirts, and information. This includes resources for teens who want to wear the shirts to school to protect themselves from unconstitutional administrative harassment. This includes a letter outlining students' free speech rights from the Thomas More Law Center.
Here is one from CatholicPosters for those of us born after Roe:
So, if you have a pro-life t-shirt, wear it proudly!
Two of many places to get them:
American Life League
National Pro-Life T-shirt Day