oil pump

I have a 89 camaro 350 tpi, changed the oil about 3 weeks ago, got in the car today drove it to work, by the tome I got there noticed there was no oil pressure on the gauge checked the oil it say its full. Drove the car car home same thing no oil pressure as car sat and idled saw blue smoke coming out of the exhaust. How do I check to see if the oil pump is bad or if it electrical

if you had no oil pressure the fuel pump would be shut off automatically to prevent engine damage. It's a safe bet your problem lies in wiring/guage.

Theres no knocking or ticking from the motor just in case?

thanks I'll ckeck out the wiring this weekend is there a sensor or sending unit for the oil pump?

no pinging or ticking just blue smoke when idling and reving at idle

Blue smoke = burning oil