best model and last model path would be different if your best model is not your last model.
Model checkpoint callback will save the models in a folder like this - my/path/epoch=0-step=10.ckpt
.
Once your training is completed you can access the location of best model and last model using the attributes
checkpoint_callback = ModelCheckpoint(dirpath='my/path/')
print(checkpoint_callback.best_model_path)
print(checkpoint_callback.last_model_path)