Is hearing your voice in your head schizophrenia?

Recently I came to the realization that I spend all the time in my head, thoughts, communicating with myself and this has been happening for a long time.
 I read that schizophrenics do not hear their subvocal voice as their own, but as someone else's, thus, when they hear other people's voices in their head, they perceive them as their own voice, because they cannot distinguish from their own voice.
And when they talk in their head (to themselves)as everyone does, their vocal cords are straining.

I noticed that my ligaments are straining too, my voice in my head is loud and as if I'm talking in reality, and now it seems that I've been communicating with someone else's voice in my head all this time, what should I do now?