I do believe the butterflies are "sent" by your dad. I'm glad you were able to have that experience today. I'm sorry it made you cry, but it sounds like you were able to have some good memories. When my uncle died, a scissor-tailed fly catcher (his favorite bird) flew right beside the car right at our eye level for about half a mile that my aunt and I were in as we left the cemetery after his burial. We just know it was him telling us that everything is OK!