I've recently asked my employer if i could take my vacation time without taking time off from work. So I worked 27 hours plus 40 hours vacation time should my 27 hours be considered overtime.

No. Overtime is based on hours WORKED, not hours paid. If you worked 40 hours or less, no overtime is due no matter how many hours you are paid for.

I've recently asked my employer if i could take my vacation time without taking time off from work. So I worked 27 hours plus 40 hours vacation time should my 27 hours be considered overtime.

You get paid overtime if you work over 40 hours. You only worked 27 hours.

No overtime is owed.