PHP查询返回false

Hey guys :) So I have a register page, but my query returns boolean false, and I can't find any solution to fix it.

<?php
  session_start();
  if(isset($_SESSION['username'])!=""){
    header("Location: index.php");
  }
  require_once 'dbconnect.php';

    $username = strip_tags($_POST['username']);
    $email = strip_tags($_POST['email']);
    $upassword = strip_tags($_POST['password']);
    $medic = strip_tags($_POST['medic_input']);

    $username = $dbcon->real_escape_string($username);
    $email = $dbcon->real_escape_string($email);
    $upassword = $dbcon->real_escape_string($upassword);

    $check_email = $dbcon -> query("SELECT username from tbl_users WHERE username='$username'");
    $count=$check_email->num_rows;
    var_dump($count);
    if($count==0){
        $query = "INSERT INTO tbl_users(username,password,email,medic) VALUES ('$username','$upassword','$email,'$medic')";
        var_dump($query);
          if($dbcon->query($query) === TRUE){
            header('Location: login.php');
          }
          else {
            echo "Error while registering. Please try again!";
            var_dump($dbcon->query($query));
          }
      }
      else {
        echo "Your username already exists!";
        }

    $dbcon->close();
 ?>

The count dump is giving 0 but for the query it's giving boolean false. I tried to change the table, didn't help. When I try to register it gives me "Error while registering. Please try again!";

You have syntax error in your INSERT query and it's missing a single quote as below

VALUES ('$username','$upassword','$email,'$medic')
                                        ^... Here