Was i molested when i was young? Please help!?

Okay, if your young child (around 4-6) came to you about a dream that was bothering her, and she told you (and im wording best i can exact) "i dont remember it all, i was in here (moms bedroom) and a man picked me up and put me on his leg. He unzipped his pants and undid (un-buttoned) them and i looked away, and then i woke up." would it bother you? I remember doing this very well, and i sure as heck know i didnt 'wake up' i just didnt remember what happened later. I dont really want to. I. Also going to add details i didnt tell my mom. I was in my underwear, and a white shirt or something. He was sitting on the bed with his legs open (wearing pants) and picked me up from behind. I remember every feeling, and that his hands were on my breasts as he did so, and then he put me on his lower thigh (like right above his knee)... I remember looking down at him un-doing his pants, and then i looked away, but half looked back, but i dont remember what i saw, who it was, or what was next, but i know i didnt 'wake up'. What if your young child said that to you? And do you think it is a dream or a memory, being so young? My mom said those dreams were normal. Ive always known what sex was and by the time i was 8? I began looking through mags to find hot guys to imagine... Things... At night. It lead to more and i became addicted to porn, and the things i watched scared me. I finally mostly stopped with porn, though. What do you think of this, also? Such a young kid doing things like that, and the 'dream'? Also, my half sister (same 'father') was molested early on, and we both have nearly every feeling in common. We are so alike, and i didnt know what happened to her until two nights ago. (ill kill the sick ++++ who hurt her, i swear) but anyway, please help i want to tell my mom what i think but i want advice first?