I recently read a book that said the 2015 Feast of Trumpets might be the first day of the 7000th year which arguably is the time for the Millennium, but if that were true then should not the rapture have taken place 7 years ago first? Or can it be possible that the rapture could still be considered the beginning of the Millennium?
You’ve answered your own question. This can’t be the year 7,000 on the Hebrew calendar and here’s why. If the millennium was scheduled to start then the Lord would be arriving momentarily, the rapture would have happened at least 7 years ago, and all the end times judgements would be winding down. Therefore, it can’t be time for the Millennium to begin. By the way, according the the Hebrew calendar, the year 5,776 is about to begin.