Check your dipstick - if there is an aperecable amount of fuel in your crankcase, the level will be high.

Feel the oil on the dipstick - is it thin? Check the feel against the dipstick of another car.

Smell the dipstick - does it smell like fuel.

If any of those tests indicate fuel in the oil, an oil change is in order - very soon!

If you change the oil immediately, think of the cost, not the entire cost, but the mileage until a change would be done.

Once my dealers's service writer put the mileage in place of the regular service called for - they installed a new timing belt 40K miles too early - I told them that I would pay 60% or the cost because I lost 40% of the old belt. They refused any payment for the belt replacement.