Membership.GetUser is null after Membership.CreateUser

 Hi, I tried this
Membership.GetUser
after this
  [HttpPost]
        public ActionResult Register(RegisterModel model)
        {
            if (ModelState.IsValid)
            {
                // Attempt to register the user
                MembershipCreateStatus createStatus;


                Membership.CreateUser(model.UserName, model.Password, model.Email, null, null, true, null,
                     ...