By and large, even if your head was larger than normal, no one would think anything of it. Head size is just not something people consider.
That doesn’t mean you might not find some jerks that tease you, because bullies will find anything to tease you about. It’s not about it actually mattering. It’s about making you feel bad. If these bullies exist, you should not let them win.
But, I think it’s likely no one has ever said anything about it to you. And, in that case, it’s just that weird effect where we think we are the stars of our own lives–that everyone is looking at us and judging us. They aren’t. Very few have likely noticed, and pretty much no one cares.
You can’t live your life being worried about the imperfections in your appearance. If your head was too big, what could you do about it? Do you want to live a life running away from people? Believe me, it’s not fun.