My boyfriend did not give me his Instagram password when I asked for it..

I genuinely wanted to do something which I couldn't from my account so I asked for his password but he refused.

Should I be worried?

*UPDATE* - so it's been a week since that incident and he still hasn't contacted me. Usually when I get mad at him, he texts me pretty quickly (much quicker than his usual texting patterns). But it's been a week today and nothing. Could he be mad at me if he thought I was trying to invade his privacy?? I am really worried. I don't want a major misunderstanding between us because of something so stupid. What do I do?? Do I text him??