Blocking Caller ID

I'm having a little bit of an anxiety attack. I called a number and I'm pretty sure I made my number private, but I'm freaking out now.

Here's the story.

I still haven't updated my iPhone5 to the newest upgrade. I went to Setting>Phone>Show My Caller ID>OFF. I did this previous to making the call. I called from my cell (in Canada) to a number in the US. I'm not sure if the number is a cell phone or a land line.

Today I'm have a totally unwarranted stress-fest over my number potentially being exposed.

My question: Even though I selected to block my number on my phone, is there a way that my number may have been potentially exposed?

Thanks in advance!