Instagram says don't panic, your timeline is not changing right now11
Almost two weeks ago, Instagram announced that it would be changing how subscribers' would be receiving their content. Instead of a user's timeline being arranged in chronological order, this content would be posted in order of importance to the subscriber. That would be determined by using an algorithm.
By doing this, each Instagram subscriber will get to see the messages perceived as being most important to them arriving at the top of their timeline. The only downside is that with the change, a subscriber could end up missing out on some messages that he/she wouldn't normally miss.
Today, a number of Instagram users started to panic when it hit them that their timeline was testing out the new algorithm. In the midst of this panic, Instagram tweeted a message to subscribers telling them not to worry because "...nothing is changing with your feed right now. We promise to let you know when changes roll out broadly."
In other words, if you're an Instagram user, there is nothing to panic about, at least for now.
source: @Instagram via Engadget