Reading social cues and fear of overthinking

Hi everyone. 

So something just happened to me that made me overthink A LOT.

It's about a certain teacher in my university. 

I wrote a test in wrong format and I was the only one to do that. In the hall, when everyone was lining up to submit the paper (the hall was very full), I approached him in the hall (far from the crowd) and I told him that I wrote in a wrong format (not really a big problem).

We were standing infront of each other, and we were the only one in that spot. He dropped his jaw, frowned a bit and froze. I was like in my mind, "he was so dramatic". I glanced at him and saw that he was just staring at my eyes with wide eyes intensely for several seconds. I looked at the floor due to embarrassment, and glanced up and saw he was looking somewhere below my eyes on my face.. then quickly averted back to my eyes. Then he softened his face and eyes, but to very neutral face, less widened eyes with no emotion, but intense eyes for like almost 1 minute. No blinking no moving at all. His body was leaning towards me (he is taller than me). Just looking at my eyes.

Then after a minute or so, he told me to just submit the paper

Sometimes when he was walking in the hall and i am standing there, he would just stare at my eyes without expression and even tilts his head to me to continue stare at me as he passes by.

He's pretty young and good-looking (he may not be good looking for many people but he is for me)

I wanna know if I am overthinking things?there are other scenarios too but I'm not gonna type it out in this text wall..

Maybe I overthink? Maybe not? But that's what happened and so far no one can tell what just happened. Like why he did that