Hi National, while 10 questions does appear to be on the lower end (I had about 18-21), I think if your answers had substance you should be in the clear.
I also am under the impression I underperformed at my interview. I thought I blew 2-3 softballs and even froze up for ~6 seconds on a pretty easy one. On the flip side, I was quite charismatic throughout the whole process, even getting a few laughs out of my interviewers and from Dee herself!
Honestly, I have no way of knowing until March 30th, but I'm not sweating at all because I will be very happy with attending Kellogg, to which I have already been accepted, as well.