Too many stitches or not enough?

[sissyv]

I am making a sweater for my husband. I dont know how many stitches I started with but I casted off 18 (9 each - two rows) for armhole shaping- so both are the same (I knit front and back at same time) so anyway, I'm getting ready to do the neck part on the front but according to the pattern (following instructions for large size) I should have 156 Stitches- I only have 146. So I'm a little confused as to how this will affect the pattern and how I go about if from this point.
http://www.patonsyarns.com/pattern.p...4209&cps=21191
Thanks