Can a drug screen determine how often/how many percocet have been taken over the last month?

Added 3+ months ago:

I am on percocet for a neck injury that needs a 6 level fusion. I don't have the money for it yet. My pain management doc has me on percocet 5mg/325 3Xday. It's just not enough some days. I've even told him so. So, some days I take 4, and others I take 2. Will he be able to tell I haven't taken it exactly as perscribed?