I have noticed this, My page was on the first page of google search result and after 2 days it disappeared. I am worried. Any idea or suggestion about this?
There can be many reasons because google is working on his algorithms since long time and we have to follow many of them to manage ranking online, may be your competitors are doing well against your ranking. Now many algos for different type of websites like for mobile web, normal desktop web. Let us know your website URL and keywords on which you were doing well before few days, then after we can give you better and detail answer.
Google works in mysterious ways. There are many factors and Google could have just re-ranked the website. Ensure that you check your content and make sure it is unique. Google loves unique and useful content.
Google is tricky. So there are a lot of reasons for that, I found the most spread of them: Google has not indexed your website yet (too new) Your website isn’t optimized for search engine crawling Your keyword market is very competitive Your website has “no index” tags Your website has been penalized and removed from Google