Thanks so much!! No just to the floor. After I held him and he went right back to sleep, hes seemed just fine.
Falling off the couch is probably not going to harm the baby, even if the baby was assisted by a two year old. It's not like the 2-year-old could lift the baby up and swing him, or anything. Do you have any evidence the baby hit something sharp, like the sharp corner of a table, with his head? If not, just keep your eye on the baby. Unusual drowsiness, or one pupil dilated and the other not, would be signs worth taking the baby to the doctor over.