Have been building PBN links to my site for a while now and it has been ranking in the 1st or 2nd page for several keywords for around a month. However, recently I stopped adding new PBN links for close to a week. Now I just checked the rankings and to my horror, many of these keywords DROPPED 20-30 positions to the 2nd, 3rd or 4th pages overnite! It is worth noting that everything was fine around 5-6 hours ago. Is anyone experiencing the same thing? Checked GWT, and everything is clear. All the PBN sites are also indexed. Should I continue with linkbuilding, or pause for now? Any advise will be MUCH appreciated.