Django DeleteView doesn't delete the object from data

I’ve just learned CreateView UpdateView and DeleteView models and then I got all of them working. I can change my object I can delete them, but after deleting an object I try to create another and creates one like the before hasn’t been deleted. giving me the following pk of the deleted before

it still creates de object although the pk at the moment should be 3, I think after I click the delete button and confirm delete it isn’t deleting from data.

These are my models:

from django.db import models from django.urls import reverse

class Dreams (models.Model):
    titulo = models.CharField(max_length=100)
    objetivo = models.CharField(max_length=100)
    imagem = models.CharField(max_length=100)

    def get_absolute_url(self):
        return reverse ('webdeve:index', kwargs={'pk': self.pk})

    def __str__(self):
        return self.titulo + ' - ' + self.objetivo


class Which (models.Model):
    lets = models.ForeignKey(Dreams, on_delete=models.CASCADE)
    make = models.CharField(max_length=100)
    it = models.CharField(max_length=100)
    favorite = models.BooleanField(default=False)

    def __str__(self):
        return self.make

my views.py:

from django.views import generic
from django.views.generic.edit import CreateView, UpdateView, DeleteView
from .models import Dreams, Which
from django.urls import reverse_lazy


class IndexView (generic.ListView):
    template_name = 'index.html'

    def get_queryset(self):
        return Dreams.objects.all()

class DetailView (generic.DetailView):
    model = Dreams
    template_name = 'detail.html'

class DreamCreate (CreateView):
    model = Dreams
    fields = ['titulo', 'objetivo', 'imagem']
    template_name = 'dreams_form.html'


class DreamUpdate (UpdateView):
    model = Dreams
    fields = ['titulo', 'objetivo', 'imagem']
    template_name = 'dreams_form.html'

class DreamDelete (DeleteView):
    model = Dreams
    template_name= ('dreams_confirm_delete.html')
    success_url= reverse_lazy('webdeve:index')

my urls.py:

from django.conf.urls import url
from webdeve import views

app_name = 'webdeve'

# Dreams

urlpatterns = [
    url(r'^$', views.IndexView.as_view(), name='index'),

# Dreams/detail

    url(r'^(?P<pk>[0-9]+)/$', views.DetailView.as_view(), name='detail'),

# Dreams/detail/add
    url(r'^dream/add/$', views.DreamCreate.as_view(), name='dream-add'),

# Dreams/detail/Update

    url(r'^dream/(?P<pk>[0-9]+)/$', views.DreamUpdate.as_view(), name='dreams-uptdate'),
# Dreams/detail/detete

    url(r'^dream/(?P<pk>[0-9]+)/delete/$', views.DreamDelete.as_view(), name='dreams-delete'),

]

And my index.html with delete button:

<!-- linkando css no html -->
{% extends 'base.html' %}
{% block nav %}

      <ul>
        {% for Dreams in object_list %}
            <a href="{% url 'webdeve:detail' Dreams.id %}"><img src={{ Dreams.imagem }}></a>
            <li><a href="{% url 'webdeve:detail' Dreams.id %}"> {{ Dreams.titulo }} - {{ Dreams.objetivo }} </a><li>

            <!--delete BUTTON-->

              <form action="{% url 'webdeve:dreams-delete' Dreams.id %}">
                {% csrf_token %}
                <input type="hidden" name="dreams_id" value="{{ Dreams.id }}" method="post" style="display: inline" >
                <button type="submit" class="btn btn-default btn-sm">
                  <span class="glyphicon glyphicon-trash"></span>
                </button>
              </form>
        {% endfor %}
      </ul>
{% endblock %}