How to create a spline representing an airfoil surface

Hi!!!

Im struggling trying to create a basic script which would plot the nose part of an airfoil. I have 4 points (+ the leading edge position) defining the upper surface and 2 defining the lower one. I have tried to split the shape in 2 and plotting the upper and the lower surface separately. This is not working out though. Instead of getting a nice smooth surface, I am getting a very wavy and oscillating pattern, with huge spikes in between 2 defined points. I have tried both cubic spline and least square method but with no luck. Any suggestion on what I could try to plot an nice and realistic airfoil shape based on the points I have??

Thanks!!!