Yeah, you probably could...but HPS lights will cause your plants to stretch...a lot. I don't know what the spectrum is on the LED you have, but unless it's specifically for flowering I say veg with the LED.
Another option is if you use a digital or switchable ballast, you could just pick up a MH bulb to veg with.
The led is made to veg and flower. The LED is going to be the light i will flower with... just wanted to know if it is safe on the plant to veg with the HID and then bloom with the LED.