The engine oil level was up to middle of the dip-stick, is this regular consumption of the engine oil?

I bought a used car a month ago. I changed the engine oil from a known mechanic. The engine oil was up to the full mark. I drove almost five hundred and fifty miles, the engine oil level was up to middle of the dip-stick (just above low and below middle point of the dip-stick). I want to know, is it the regular consumption of the engine oil, or my car is using much than the normal? There is no leakage of the engine oil. No smoke from the muffler. Good pick-up, the engine is clean, no noise and no smoking, smooth running. Thank you for your time.