94 polaris 300 question

I have a 94 polaris 300 – first 4 whlr ever – have an oil question.
When we bought it – the owner said something about just adding the oil in with the gas each time. Ok – we have been doing that and no problems. We have had this for about 6 months using just to ride back in the fields with the kids and such. We really know nothing about fixing or repairing or anything like that. We all of a sudden now there is a red light on which we are assuming is an oil light. Do we need to check into this since we are adding the oil as we add gas?

Lorry