The following is a quote from the IRCC website
http://www.cic.gc.ca/english/information/security/police-cert/intro.asp
So if the certificate was issued more than 6 months ago, you sure need a new one because you left Egypt "after" the certificate was issued. Do not assume that they will not care about these few days spent in Egypt after the certificate was issued. They do care and some people were rejected because of that.
If the certificate was issued recently, then I am not sure if they will go by the 6 months rule in the quote above. Or they will go by the 3 months written on the certificate. But I think it is safer to get a new certificate (apply from outside Egypt) if the one you have was issued more than 3 months ago.