When I come into my office my monitor is completely blank, the power light is on but flickering, I unplug vgi and power plug them back in and it comes on, sometimes have to repeat process 2 or 3 times

Sounds like the video card is on the fritz. Or loose. If your allowed open the case and see if the video card is secure. Sometimes when its loose it will look like its in but won't have a good connection. So it will do what your describing. If it's loose it should make a "click" sound when you push it back in the slot. If that isn't it you may need a new video card. How old is the computer or video card?

Typically, a blinking monitor light could indicate that the PC has gone into sleep mode or has no input from the motherboard/card (PC is shut off). If you have sleep mode settings that automatically take effect after so many hours of inactivity, the system will go into sleep without your input. When you unplug and replug stuff you may trigger a come out of sleep cycle. Normally to get a PC out of sleep all you have to do is to move the mouse or press a key on the keyboard and these choices are set in the bios. If nothing is set and the PC is allowed to sleep there is no way to get it out easily.

If you decide to mess with the card as mentioned by Gryph, make sure to completely power down (unplug from the wall) before you reseat the card. Swiping the gold finger contacts of the card with a small piece of brown paper bag (rough paper) will often clean them enough to get a good connection back. Check your connections both at the PC, the Monitor and the Cords for any loose connections or missing or bent pins.