Hello I am 24 years old.since last 3-4 period cycle I am observing that though I am getting regular periods but I get only for 2 days and that too flow is little.
I am scared to death as what's wrong with me?
Kindly help me out.

Why scared to death? By 24 you should know and realize, that cycles will and can vary. Also, late or even missed periods happen.

As to why you have had the change, can not be determined over internet, you need a complete exam

There may not be anything wrong with you at all. It can be perfectly normal to have periods that last just two days, and this may now be a new norm for you. However, since this is causing concern, see your gyn and have an exam as Fr_Chuck suggested.