I have a 2002 Dodge Dakota 3

I have a 2002 dodge dakota 3.9 liter v6 and am having oil problems. The owner before me had overfilled the oil, that problem has since been fixed. But now I go through way too much oil. I put 3 and a half quarts in at the beginning of the month and the dipstick is telling me to add more now, where is my oil going, no leaks, no smoke, no burning oil smell, its just disappearing, can you help me?