So, I am a high school senior who was originally planning to apply to both UMass Amherst and Amherst College. I ended up only applying to Amherst College, and this was reflected on my transcript request when I turned it in at the beginning of December. However, I submitted my Amherst Coll. application a few hours ago and have just realized that my school counseling office sent my information to UMass instead. 
Is it possible that Amherst will accept my transcript/recommendations a few days late?
It’s going to be fine. Call the admissions office and let them know what happened. I’m sure that this has happened before.