Cant do a rounded picture box, help me : im having a problem to round a picturebox edge on visual studio enterprise 2015

            private void pictureBox3_Click(object sender, EventArgs e)
        {
            System.Drawing.Drawing2D.GraphicsPath gp = new System.Drawing.Drawing2D.GraphicsPath();
            gp.AddEllipse(0, 0, pictureBox1.Width - 3, pictureBox1.Height - 3);
            Region rg = new Region(gp);
            pictureBox1.Region = rg;
        }

this is the code, but nothing happens, could you help me?