Please help!! no oil pressure after oil change!!

OK, thanks!
I'll try the suggestion you gave.
As for the oil, it's 20W-50 as I always use on this engine and when I drain it comes out little more than four quarts and the service manual for my engine says 4 quarts and if I fill a little more than 4 quarts i got the MAX limit on the oil stick so I think it's the correct capacity for my pan.