Car running with the oil light on

[ebpda9]

this happened last week, and i thought i had some screwd up oil in the car, so i changed it. this morning i was late for one of my classes and i had to push the car harder on the freeway, and when i got off the exit the oil light came on at idle. as soon as i rev the car a bit it goes off but when it gets to the idle again the light comes on. i was lucky it happened only at 1 minute away from school, so i parked it and went to class. when i came out i chaecked the oil level and it was at the same level as i filled it up last week. i went home normslly on the freeway and the light did come on. checked the oil again and it's still at the level. i take the oil cap and i have oil blown out of the crankcase. it's all good the oil pump is working, but why in hel is the light coming on ? i talked to my dad and he said it might be something on the fuel lines, or a vaccum leak that could trigger the light. what do u say about this ? i'm really out of ideas