Is defending a master’s degree an appropriate time to say Hallel?

I am defending my master’s degree in several days. This is the culmination of five years of undergraduate and graduate education. I intend to stay in school for a PhD, but most likely after an off semester or two – which will mark the first time I haven’t been a full-time student at one kind of school or another during a fall or spring semester since I was four years old. I may or may not be staying at the same institution (which I suspect may change things, insofar as if I go elsewhere it’s a more momentous life-changing event than if I don’t).

I’ve gathered that opinions vary on the degree of celebration involved, but that, for instance, I am not permitted to listen to music with instruments that day because it’s at least not sufficient to override sefira.

However, what about Hallel? If my defense is successful, can/should I say it? It’s noted that it is appropriate to say at celebratory events, but I believe that I think, at bare minimum, a shehecheyanu is appropriate.