Oil question

This may be a dumb question, if so I apologize in advance but I'm a first time owner and wasn't sure if this was normal or abnormal.



Was driving around the other day and the low oil light came on, so I made my way home and parked it in the driveway. Went to advance auto got oil and a filter for a change. I started it up just to check the oil level and the car was running rough so I shut it right off.



I did the oil change, started it up, let the CPU check the level (it's good now) and the car is running fine again. My question is:



Do the e90's typically lose oil just from normal driving conditions and need to be topped off regularly? I bought the car approx. 4 months ago, I've only put about 2,000 miles on it. I ASSUME the oil was changed when I purchased it. But when I changed the oil, only about 5 quarts came out. Seems like a LOT of oil to be burned off considering I haven't noticed the car burning oil, I haven't smelled anything, and I haven't seen the infamous white smoke from the exhaust. I've never owned a vehicle that just sort of, LOST oil from driving unless there was an underlying issue.



Thanks in advance!