He gave me his ex's engagement ring

I'm not to happy about how I got my ring from my bf. Originally he bought it to be engaged to his ex. He was trying to sell it on facebook a while back. Then he gave it to me. I'm not sure how I should act about it. I kind of feel unimportant because he gave me the ring he bought for someone else but I don't want to be that girl friend that freaks out over that kind of stuff. Any advice?