As I suggested, the edges don’t lie in the same plane. The Y values should all be the same in this view. Clearly they aren’t.
As Simon indicated, it is easiest to draw the shape on a large rectangle to know you’ve got all the edges on plane.
also, when you are drawing circles, make it a habit to drag out the radius on axis. In your model it appears you’re dragging the radius out in random directions each time. That makes your model much more difficult to work with than it needs to be. If you tried to get that profile out of your exisitng shape, your random drawing of the circles would contribute to the problem you have.