When using Data augmentation is it ok to validate only with the original images?

Question

I'm working on a multi-classification deep learning algorithm and I was getting big over-fitting:

My model is supposed to classify sunglasses on 17 different brands, but I only had around 400 images from each brand so I created a folder with data augmented x3 times, generating images with these parameters:

datagen = ImageDataGenerator(
    rotation_range=30,
    width_shift_range=0.2,
    height_shift_range=0.2,
    shear_range=0.2,
    zoom_range=0.2,
    horizontal_flip=True,
    fill_mode='nearest')

After doing so i got these results:

I don't know if it's correct to do the validation only using the original images or if I have to use also the augmented images for the validation, also is strange for me to get higher accuracy on the validation than the training.