I tossed my 2 yr old on the bed today & he flipped & his head bent far back. He cried for 1 min but was fine all day. Do we need to watch 4 any probs?

Probably fine. Kids are a lot tougher than parents seem to think these days. He was probably more startled by the experience than hurt. Watch how you toss him around, but don't feel like you are going to accidentally break him either.