You should remember that the EMA said that :- "This is a maximum timeline and every effort will be made to bring the Regulation into application as soon as possible....progress of implementation of the system will be closely monitored ...and hence application of the Regulation to an earlier time as possible".
The EU clinical trials portal and Union database stakeholders meeting (08Dec2015) their plan, stated (information issued 15 Dec 2015), that the regulation would apply from 4Q 2017.

So the timeline of Oct 2018 is a maximum, but the people working on the portal think that the Regulation may apply from 4Q2017. Be prepared!