Do you have any eye pain?
It is possible that the contact lens has already fallen out.
try to rinse your eyes again. pull the upper eyelid away from your eyes and rinse under your upper eyelid.
Fortunately, there are not many places for a contact lens to hide.
If you believe the contact lens is still there, you see an optometrist or ophthalmologist in the morning.
since you are not in serious pain, it would be best to wait for your eye doctor in the morning.