Was I sexually abused?

I know this is an odd question. A question I should know the answer to, but the truth is, I have absolutely no idea.
It happened when I was 6 years old, I had this friend that was year older then me and I used to be at her house every single day after school.
I understand that kids might try things out with their friends and the first time she made me undress and before touching me I might even have considered it nothing more then just two innocent kids being foolish. But I felt awful and then it kept happening over and over again. She would force me to do this "game" with her. Making me touch her, to make her feel good.
It went like that for weeks or even months. She would force me, blackmail me or even bribe me. That's exactly what happened the last day I saw her. we had been playing outside in the snow and I was cold and the only thing I really wanted to do was to watch this movie she had and she agreed that we could watch it but first we had to go into her bedroom and do her favorite game. The strange thing is, I always came back to her after she hurt me, I wasn't scared, not really. I mean I could play with her in the living room or 'cook' with her in the kitchen but her bedroom scared me to death because I knew exactly what she wanted to do once we'd go in there.
Now what I want to know, is this just something normal that happens between two young friends or is this something bad?
I don't know, I've just been feeling quite horrible about this lately and I feel like telling my mom about this but I don't want to worry her and embarrass myself if this is perfectly normal, you know??
Well I hope I get answer soon!