I have 11 wordpress sites (2 years old), with 6 unique articles on each. Sites hadn't any backlinks. Now I created 10 web 2.0 backlinks on various web 2.0 properties to every wordpress site.. From 110 web 2.0 backlinks are 17 indexed (I don't make backlinks to them so far). After 3 weeks 6 wordpress sites got deindexed by Google. Is it normal?