Triangles overlapping in mesh

I am trying to procedurally create a circle mesh using triangles. The code works fine and does create the mesh as expected in most cases but there is an issue when the triangles are not in a uniform circle as shown in the image below. What happens is, the triangles end up overlapping or stepping out of the vertices boundaries.

How can I detect when a triangle is about to reach another vertice to make sure they don't go out of bounds or overlap and stop it there?