this code show me the error of connection(The connection was not closed. The connection's current state is open.")

using System;
using System.Collections.Generic;
using System.Linq;
using System.Configuration;
using System.Data.SqlClient;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace projectDressDesign
{
    public partial class registration : System.Web.UI.Page
    {
        SqlConnection myConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["DefaultConnectionString"].ConnectionString);

        protected void Page_Load(object sender, EventArgs e)
        {

        }
        protected void registerBtn_Click1(object sender, EventArgs e)
        
            {
                Page.Validate();
                if (Page.IsValid)
                {
                    myConnection.Open();

                    string userInvalid = "The username entered is invalid, please choose another.";

                    string checkDatabase = "SELECT * FROM Users WHERE Email_Id = @em AND Password = @pas";
                    SqlCommand command = new SqlCommand(checkDatabase, myConnection);
                    command.Parameters.AddWithValue("@em", email.Text);
                    command.Parameters.AddWithValue("@pas", password.Text);
                    command.ExecuteNonQuery();
                    SqlDataReader reader = command.ExecuteReader();

                    if (reader.HasRows)
                    {
                        outputlabel.Text = userInvalid;
                        myConnection.Close();
                    }
                    
                
                else
                {
                   
                    outputlabel.Text = "Succesfully Registered";

                    string query = "Insert into Users (FirstName,LastName,Gender,DateOfBirth,Email_Id,Password) Values (@fn,@ln,@gen,@dob,@em,@pas)";
                    myConnection.Open();
                    SqlCommand insertCommand = new SqlCommand(query, myConnection);
                    insertCommand.Parameters.AddWithValue("@fn", fname.Text);
                    insertCommand.Parameters.AddWithValue("@ln", lname.Text);
                    insertCommand.Parameters.AddWithValue("@gen", gender_dd.SelectedItem.Text);
                    insertCommand.Parameters.AddWithValue("@dob", date.Text);
                    insertCommand.Parameters.AddWithValue("@em", email.Text);
                    insertCommand.Parameters.AddWithValue("@pas", password.Text);

                   

                    insertCommand.ExecuteNonQuery();

                    myConnection.Close();
                    Response.Redirect("login.aspx");
                }

                    
            }

        }
        }
    }