While ATC will always try to vector you so that you intercept the localizer while still below the glideslope,, occasionally circumstances result in you being slightly above the GS on intercept. This is usually due to a wind that pushes you into the ILS early or ATC attempting to squeeze you in ahead of someone else which results in a short gate.
The bottom line is you should have the skill to transition from a moderately above the GS glide ILS capture, to a stabilized on loc, on GS, flight path. Of course continuing the approach is always at your discretion and if ATC leaves you high and dry you may be forced to abandon the approach and go missed.
This is one area where situational awareness is really important. Good SA will alert you to the possibility of an above the GS capture early allowing you to prepare for it.