Get ready for a brain freeze and a sugar rush! This Saturday, April 13th, 7-Eleven is bringing back its iconic “Bring Your Own Cup Day” event, offering Slurpee fans a chance to fill any container of their choice for just $1.99. Here’s the Scoop: Date: Saturday, April 13th Locations: Participating 7-Eleven, Speedway, and Stripes stores Price: $1.99 per “cup” (any…