My website http://schoolpro.ifconit.com/ was on 7th page before yesterday.. As you can see it's a sub domain of my main website http://ifconit.com. But today when i checked my website on google search i cannot find my sub domain. I can see my main domain on 10th page.. But the strange thing is that whenever my main domain appears in search results, sub domain gets disappear. Why this happening everytime? Keyword is "Web Based School management software"