Peter T. Pacik, MD (retired)

Women who workout do not like the deformity created by the implants that move all the way to the clavicles (collar bones). It is for this reason that I mark and stop my dissection about two inches below the collar bones to avoid this animation deformity. This still gives enough space for the breast implant to look natural.

I encourage my patients to get right back into doing light exercises (without flyes) as soon as they feel up to it. There is no harm in doing curls or lower body exercises. They are encouraged to start moving their implants on the day after surgery. Many patients have minimal to no pain as a result of indwelling pain control catheters.
Moving the implants after augmentation mammoplasty helps the rapid return of feeling normal again and may help avoid capsular contracture.

Your question involves several important considerations:
It is important to measure the base of the breast which is the potential space involving the upper aspect of the breast between the sternum and anterior axillary fold. This measurement helps to make a decision between a high profile implant and a moderate profile breast implant, the latter being used for a wider chest. This breast measurement is also helpful in determining the final size of the implant to avoid the problems of a breast implant that is too large.
 A high profile implant projects more than a moderate profile breast implant and may appear larger.
A 400cc implant is always larger than a 365cc implant. The final appearance varies because the amount of breast tissue varies as well as the notation above between high vs. moderate profile breast implants This is why it is hard to make decisions surfing before and after photos on the internet because these important factors are often not known. In addition many of the photos fail to disclose the weight of the patient which also makes a difference. 
This is an excellent question and will likely help other women understand these concepts.

There are a number of reasons you may be having pain. These include peri-menopause or menopause where the tissues are not as robust as when younger and tear more easily. Even some younger women have excessive dryness and benefit from topicals such as NeoGyn or the newly released Osphena.

The vagina may be too tight from the surgery and working with dilators may be of value in combination with some of the creams noted above.

Secondary vaginismus can also be considered.

A number of treatments are available for excess labial tissues including a treatment called labiaplasty. However, the photo is of poor quality. To get expert advice it would be best to submit a better photo.