Does everyone have a spirit guide?

So I'm reading this book by Sylvia Brown and she's talking about spirit guides... I know what they are but I'm wondering is if EVERYONE has one..? And how do you know? I've tried googling to how figure out if you do or not but I just am lost! Idk if this counts but I'm 17, and when I was about 13 my mom went into surgery to remove her large intestine. I awoke in the middle of the night and saw a HUGE orb and then a smaller one sort of attached to the upper right hand corner. It was randomly when I woke up, I remember hearing myself say "Hi mom" and I fell right back to sleep. Was this my mothers spirit? How do I know if I have a spirit guide? Or how do I get in contact with them? Thanks. :)