Hi aaalex,
No. You can't. You will have to go to NB. As per their rules and guidelines, once you land in NB you have to report to NBPNP Office within 30 days. Remember, you have already signed an undertaking that you will reside in NB. You have to complete the formalities of applying for PR Card, SIN etc..etc. and for that you will have to provide an address to them and they will send the PR Card to that address once it is ready. You will have to report first to NBPNP Office. As there are no direct flights to Fredericton, Moncton and Saint John most of us will have to land in Toronto or Vancouver and then to take connecting flight to NB.
Please go through the guidelines of NB. They have the authority to revoke the nomination too.
Alwin