I have sort of the same thing happening. I will think about something and then minutes or even seconds later, someone around me will mention something about what I was thinking.
Same question...am I manifesting the thought in them (seems kind of "big-headed" for me to think that) or did I somehow know what they were going to say before they said it? This has just started happening recently.
Sorry I don't have any insight to your question, but thought that presenting a similiar instance might bring some more answers.