Hey. Thats pretty trippy. I just made a thread with something similar that happened.

It was a really long dream and I knew i was dreaming, I was even telling other people in the dream that it was a dream and at one point was talking with someone/something that was telling me how dangerous it was to be in this "world" because if you die there you could get stuck.

My other dreams, as soon as I realized I was dreaming, whatever was happening in the dream stopped and I was able to control everything.

This last one, I knew I was dreaming but had no control over what was happening, only myself. Gave me the alternate reality thing your talking about.

So much so, I called my mom and asked her if I was in her dream last night since she was in mine