Source of extended wide band low frequency noise in FFT

I have a bioamplifier using the AMP01 amplifier.

www.analog.com/media/en/technical-documentation/data-sheets/amp01.pdf

It has this 1/f noise.

But how come my actual noise (FFT) with all inputs shorted (In+, In-, ground shorted) has wide band extended low frequency noise beyond 1/f that looks like the following. What is source of the noise? Is it extended 1/f? What caused extended 1/f? And how does one convert the datasheet vertical amplitude to one I measured at FFT?