Your RRSP Contribution made in the First 60 Days of 2017 will not show up on your Notice of Assessment if you did not claim it on your 2016 tax return.
If you did not claim this amount, you will need to do an adjustment to the 2016 return. You can use "My Account" if you are set up, otherwise you will need to send a paper copy to your tax services office.
CRA info: If you deduct an amount for 2017 that you contributed to an RRSP up to March 1, 2017, which you had not previously deducted, you should have filled out and sent a Schedule 7 - (RRSP Unused Contributions) for these contributions, for each particular year. If you did not, you should fill out and send a copy of the appropriate Schedule 7 for each year, along with the appropriate RRSP receipts, to your tax centre, separate from your 2017 income tax and benefit return.