Do you think 300cc is too small at 5'1 and 121lbs? (Photos)

You need a formal evaluation by a licensed plastic surgeon and expert in breast augmentations to determine what is best for you and your goals.
Proper breast enlargement is not a "cookie-cutter" procedure where the same technique is applied to every patient. Every woman who comes to my practice has unique needs and different goals for her breast augmentation. As a board-certified plastic surgeon, I always listen carefully to each woman's concerns and thoroughly discuss the key points of the procedure. I also take into account their overall height and weight, the size and shape of the underlying chest and ribcage, the tightness and elasticity of the skin, and the amount of natural breast tissue. Prior to the procedure, we discuss and make decisions regarding location of the incision, whether to place the implant under or over the chest muscle, and what type of implant to use (I offer multiple types of silicone gel breast implants, as well as saline implants).
My experience performing thousands of aesthetic breast surgeries in a wide anatomical range of patients enables me to achieve consistently beautiful and natural results that are customized to each patient’s body type and goals. These results are the product of extensive communication, meticulous planning, and skillfully executed surgery.
I suggest consulting with a board-certified plastic surgeon and expert in Breast Augmentation surgeries. - Dr. Cohen

Dear Maisly1995,
I understand your concern and it is quite normal to be concerned about the outcome following a breast augmentation surgery. However, you are still in the very early stages of the healing process.Your will need to be patient at this moment and follow what your surgeon has instructed you to do post operatively.At the early stage of the healing process, the tissues around the implants are still swollen. Once the swelling subsides and the implants drop to their final position, you will be able to see the final result of your breast augmentation surgery.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

To answer your question about size and how many cc’s you should get based on the size you want to achieve, first you need to take into account what's known as your base width diameter.
Imagine lying on your back and drawing a circle around your breast. If you were to draw a line across that circle, it will be a given length. Your plastic surgeon will measure this length, which is called ‘’base width diameter’’ or BWD for short. For women, the base width diameter can go from 9.5 cm to 16.5 cm, or 3.75 to 6.5 inches. As you can see, there is a very wide range. 
For example, a 300 cc implant on a woman with a BWD of 10 cm is very different than 300 cc for a woman with a BWD of 15 cm. On one it may be enough volume, and for the other it may be much less than the desired result. 
As far as the placement of the implants, placing them under your muscles - this is still the most popular technique for a variety of reasons, one of the biggest advantages is that it prevents rippling and it also hides the implant better. It is probably still recommended to replace the implants under the muscle, but a discussion of your goals during the consultation will help determine the final position.
Regarding sagging, whether you have implants or not, aging, pregnancy and breastfeeding will do things to your body. When you’re pregnant, your body releases more hormones. You’ll gain weight. Your skin will be stretched by the pregnancy weight and lose some elasticity.  And after childbirth and breastfeeding, your breast will deflate and your skin will be looser. 
I hope that answers your question on size. It’s great that you’re doing this research. I always say that the best patients are informed patients.
Thank you for reading and best of luck on your journey!

The best advice would come from your plastic surgeon that examined you. Typically, breast measurements are taken and most surgeons will recommend a range in volume (cc's) that would look natural for you if that is the "look" you are going for. In my practice, I let patients try on sample implant to see what kind of implants looks best with their shape and size. I rarely go by cup size. If you are concerned, talk to you plastic surgeon and make another appointment.

I think this is a great size for you.  Right now, you are very swollen and the swelling can hide the nice contours of the implant.  Do your best to be patient as the swelling subsides. You will end up loving them.

Congratulations on having undergone the breast augmentation procedure. Although online consultants will not be able to provide you with meaningful reassurance, it may be helpful for you to know that a significant percentage of patients at your stage of recovery will feel that they are too big or (more commonly) too small. I routinely ask my patients to wait at least 3-6 months before evaluating the end results of the breast augmentation surgery. This waiting time allows patients to (usually) physically and psychologically adapt to the new body image. 
From the physiological standpoint, it takes many months ( and even up to one year) to see the final results of surgery. factors such as swelling, tissue contraction, skin redraping, implant shifting etc. come into play. You may be pleasantly surprised wants to be "drop and fluff" phenomenon has occurred. You may also be happier once the swelling AROUND the breast implants dissipates and the implants' shape and projection become more visible. 
From the psychological standpoint, patients undergo an “adaptation period" during which time they get used to the changes that the surgical procedure I would send has brought about. Severe emotional swings can also occur after any type of surgical procedure.
Although I cannot comment specifically about your anatomy and its limitations, (generally speaking) every patient undergoing breast augmentation surgery should understand that their anatomic starting point will limit the outcome of breast augmentation surgery.    In other words, a patient's starting anatomy will limit how large of a breast implant can be utilized safely. The use of a larger breast implant (than what is safely "allowed" by the patient's anatomy) can be problematic;  potential problems include breast implant displacement/malpostion issues ( such as bottoming out, lateral displacement, symmastia...) and/or significant breast implant rippling/palpability.
In your case, I would suggest continued patience and continued close follow-up with your plastic surgeon.
Best wishes for an outcome that you will be very pleased with long-term. 

Hello. Thank you for your inquiry and congratulations on your surgery!

It is important to have an in-person medical assessment regarding this issue as it is difficult to determine virtually. Continue to update your doctor in the matter and follow their post-op protocol.

Please ensure to get cleared by your doctor before engaging in specific physical activity before the 3 month healing period has ended as the healing stage is crucial for healthy results.

It generally takes around 6 months to a year to see your final results. Your tissues will take time to relax and allow your implants to "Drop and Fluff" settling into place. Should a revision cross your mind, it is best to wait at least 6 months to a year before doing so.

Our tips for recovery following breast augmentation are to wear a supportive sports bra for 3 months post-operative and refrain from lifting anything heavier than 10 lbs for 3 weeks as we don't want any strain at your incision sites. Make sure to keep the area of your stitches clean by cleansing with hydrogen peroxide daily. Showering is encouraged! But, no sitting in water for 2 weeks following surgery (no baths, hot tubs, pools etc.).

Please note that this response does not substitute patient-doctor relationship. We welcome any and all patients seeking advice to come in for a complimentary consultation available for limited time only.

During the COVID-19, we are offering complimentary online consultations as well as in-office consultation with social distancing and masks. Procedure done in-hospital private surgical facility while taking covid-19 precautions. We utilize UV-light to clean the air of viruses and bacteria during our consultations and surgery. We invite you to come in to discuss your options more thoroughly. Please send us an email at info@drkaraplasticsurgery.com with the subject line: "Attention Meagan" and we will be happy to coordinate your appointment!
M.Kara,MD,FRCSC (27+ years experience) - Specializing in 24 hour recovery/ out to dinner breast augmentation in-hospital private surgical facility for your added safety and peace of mind