Just because you can, should you?
Yes you can definitely have an augmentation and butt augmentation but implants will have to be used and its impossible to tell from photos if your waist could be made that small. Unless you're in the business of selling a look or image, its always better to wait until you're done with having your family as you know the only think you have to do thereafter is to maintain your weight. You have a great body and do not need anything but if you're intent on doing something, make sure you choose a board certified plastic surgeon to start with and find out what options are available to you.
You appear to be a good candidate for a BBL. You don't have a lot of fat, so you must be realistic about the size increase you can obtain. Butt implants are another option but implants in the buttock aren't as easy to manage as your own fat. You appear to be a very good candidate for a breast augmentation as well. There are hundreds of plastic surgeons in LA. You could spend 6 months doing consults, but coming to RealSelf is probably the best first move.
BA and BBL
You are a young adult at 18 and can do whatever you like. I would suggest you consider a buttocks implant as you do not have enough fat to make a difference. Please see example below.
Hello, thanks for sending your pictures and your inquiry. I would say that you are great candidate for wonderful results. Please make sure that you and your surgeon are on the same page. Don't forget to discuss all your concerns, options and expectations thoroughly. Have a safe and pleasant PS Journey!
Dr. Jaime Campos-Leon
Board Certified Plastic Surgeon
if you have parental consent and are cleared by your primary physician, I would go on some complimentary consultations with experts in the area and be evaluated