I feel horrible

I was hunting behind my house on the 4th day of PA rifle season. Well to make a long story short.. We have too many does around my area like 1 buck to every 14 doe! so me and my friends we gonna take 2 doe a piece. well I was in my tree stand and my bro was pushing for me, and this doe which i thought was alone came into my shooting lane. so i pulled up and fired. She dropped like a ton of bricks. Now heres why i feel bad. I accendently got a small 1 behind it. I mean a SMALL 1. and i feel horrible. From what i noticed from cleaning a butchering the large doe. My bullet went completely through and hit the small 1 in the heart.. has ne thing happened to ne of you guys before...