I checked on my intern multiple times in the last days. I said "why this still has not been worked on ..." in different ways many times. So many that I felt I was being a little XXX? What should that XXX word be? "demanding" is NOT exactly right. I felt I should not leave the intern so little "room" by constantly asking for status update.
Insistent may convey the idea you want to express:
- earnest or emphatic in dwelling upon, maintaining, or demanding something; persistent; pertinacious.