Today my check engine light came on and my oil pressure is showing very low. Oil level is fine...and there does not appear to be a leak anywhere.
I am thinking oil pump but I am not sure about that.

 

Define really low... GM states minimum hot oil pressure to be 8psi at idle and an increase of ~10psi for every 1000RPM up to around 60psi.

Have you checked the codes?

 

If it's really low from what you're used to I'd double check for a leak at the sender. Since it sits on top in the back you may not notice any drips for a while. Others have had this problem and after REALLY looking they found their sender was leaking. Doesn't cost anything to be sure.

 

here are the codes I got:
P0410
1 Circuit relay defective or fuse open
2 Check connector and wiring
3 Air pump defective or hoses blocked