Um. You really need to do it during the activation. Contact Boost and find out what (if anything) they can do after the fact. Normally if you do it on the phone or over the online Live Chat, they ask you if you want to port over an existing number. If you activated on the Boost wesbite using the form, there is a note on the page "To keep your existing mobile number, please DO NOT continue with this activation form. Instead please contact Boost Mobile Live Chat to progress the switch for you. We're available 24x7."
* I am a Boost Australia customer. This is a peer to peer community where users help each other.
