is a good read.
In terms of any social media -- Facebook, Twitter, Pinterest, LinkedIn, etc. -- remember some key points:
1. The information you post typically belongs to the place you post (this is not necessarily a copyright discussion item; just they have the data, and currently have a lot of leeway as to what they can do with the data).
2. Never assume any privacy when posting on a social media network even when using privacy settings; see #1.
3. Google indexes everything; and there are other search engines as well that do not respect any robot settings. This ties into the 1st two points above. If the network doesn't release it, chances are high other search engines have a copy anyway (that they can release, sell, etc.).
The above stated as general rules of thumb, based on "one of my class mates had reported me" I would remove all class mates from your social media areas (Facebook, Twitter, etc.) OR use the privacy settings that they are in their own group... and you take extreme care what you share to that group.
While I've been on the receiving end of HIPPA, and I'm sure I'll learn more about it should I get accepted into nursing school, what you shared that you posted should be explainable in terms of it not really being a violation.
I strongly agree with Sun0408
concerning being professional on any network.
In 2012, there was a Gallup survey once again ranking registered nurses (RNs) as the most trusted profession, based upon their honesty and ethical standards.
That is something to strive to live up to over time.