I was unable to accumulate credits until the first day of the month after my endorsement. I also did not need to pay the AMF for those few days. As eager as I was to "jump in", I also appreciated the 20 free days.
To put some dates to it, I passed the test on 28-Nov-2015; My certificate was awarded 11-Jan-2016 and I was able to start earning CPEs 1-Feb-2016. My deadline for the first 40 CPEs and the first $85 AMF was 31-Jan-2017.
To my knowledge, you may not be able to claim CPE credits for activities that occurred prior to your certification cycle start date that includes endorsement. Until endorsement is complete, I recommend making a list of archived items that peek your interest to revisit to obtain credit after cycle start date is issued.
@mmarlow Thank you for your inquiry. Please know, CPEs can only be earned during your cycle dates. Once your endorsement application has been approved, your cycle start date will be the first of the month following. For example, if your endorsement was to be passed today, your cycle start date would be April 1, 2018. That would be when you can start earning/submitting your CPEs.