Subdivision Surfaces causing round edges on wrong face location model

So I am making this face in Blender at part of a tutorial. I am at the stage near the end of the tutorial and I cannot get it to do the Subdivision Surface Modifier Correctly

The only two modifications added to the modeling process was mirror near the start making the model and new more recently adding the Subdivision Surface modifier. I tried start from the beginning many times but cannot get past this problems? I think this has nothing to do with normals right?

Thank you for help in advance, I would really like to become a really great animator/modeler in the future for blender. I want to work with the Unity Engine to, but need to get my modeling and animation skills up prior.

I atttached a JPG image to this thread so that you can visually see what is the problem.

Make sure the mirror modifier is at the top of the modifier list
In the mirror modifier ensure you have enabled the Clipping and Merge options. Ensure the vertices along the centre line are actually on the centre line, try increasing the Merge Limits value so the centre vertices get merged together

Thank you for the suggestions. I will try this!

It was as you said, the vertices were not aligned corrected with the centre linefor the mirror modifier. Thank you Richard!

I’d keep that face model anyway, even after it’s fixed. Would make an awesome mask sometime in the future.