Is it normal to have pain in your incision? Mine is under the crease and sharp pains in my nipple (Photo)

Most breast aug patients get some type of painful sensations at 2-4 weeks, particular in the nipple area as the nerves return to normal.  And the pain you're having under your breast at the incision is most likely due to the necessity of taking care of your children.  We often put deep sutures under the breast in order to prevent implant "fallout" in thinner patients.  These stitches can become painful with early exercise.  Best to consult with your surgeon as he/she would have direct knowledge of the cause of your discomfort.

Normal post operative discomfort is common after breast augmentation. Many patients even describe sharp pains from time to time during the healing process. But usually that discomfort comes and goes quickly and doesn't result in swelling (which could be a hematoma) or worrisome changes to the incision site (which could be an infection). You know your body best. If your body is telling you something is wrong, you should see your plastic surgeon. He or she will want you to have peace of mind if you're worried and will want to intervene if there is a problem.
From your photos I can't see anything that jumps out at me as being worrisome, but pictures often don't tell the whole story. If you're worried and in pain, I recommend seeing your surgeon.
I hope this helps!