I saw my ortho doc and he said i have a fractured 5th metatarsal. he gave me a walking boot and said come back in 3 weeks. is this normal procedure?

Depends: It really depends on where it is broken. If it is broken and non displaced other than the base of the bone...it is normal. He will take further x-rays to check its progress. My advise to you is stay in that boot, let your foot be your guide and let it heel.

Yes: Yes this is routine. Typically these heal without surgery. A walking boot for a few weeks is appropriate care.