How Early Can Capsular Contraction Start and What Are the Symptoms?

Congratulations on your procedure. Capsular contracture typically takes several months to start forming. One breast will start to feel more firm than the other. In severe cases the breast with the contracture can become painful and appear higher and tighter than the other side. It's important to remember that breast implants take a full six months to settle fully. You can have areas that appear flat a deflated at the bottom of your breast and it's just because the implant hasn't settled fully. It goes away with time. Over the next several months your breast should become more round and full. If you have concerns, reach out your plastic surgeon for specific answers.

It's quite early into your healing. Hence, it's not likely you are experiencing capsular contracture. Your #healing will continue for 2-3 months for the early period. This includes some #swelling, bruising, malposition, color differences and sensation will be abnormal. Scars will also be changing.
But, it can be up to one year see your final result. Your doctor may require you to move or massage the implants within the breast pockets during the #postoperative period. (#Textured implants do not require breast massage.) 
Severe capsule contracture probably occurs in less than 15% of augmentation patients. Every woman has a breast capsule around their implant and this is a normal phenomenon. The capsule itself could be as thin as Saran Wrap but may also become calcified and thickened. As it thickens and shrinks, the patient may develop a feeling a firmness of the breasts and in its worst situation, the breast may become painful and abnormal in appearance, achieving a very round, hard, and uneven appearance. There may be distortion and possible breakage and leakage of an older implant, but may also include a newer #implant.
Saline implants may deflate spontaneously. When the patient has significant #symptoms, complete or partial leakage of their saline implant, or concerns regarding silicone leakage, it is recommended that the implant is removed and exchanged. 
You must have patience as you heal, but if there are any causes of concern, ask questions of the doctor or the nursing staff

Fortunately it is very unlikely that you've begun developing capsular contracture 10 days after breast augmentation surgery.  It usually takes at least a couple of months for a well developed capsule to develop first.  It is also very common for one implant to settle sooner than the other side.  This is not usually a concern. Hopefully your Plastic Surgeon is readily available to answer your questions and address your concerns through the healing process as well.