I can feel a hard-ish tender lump just under my scar, is this my internal stitches? (Photos)

Thank you for sharing your question and congratulations on your breast augmentation.  Most commonly tenderness along your incision line is due to the sutures placed underneath your skin at the time of surgery.  Though it can not be seen in your pictures I would contact your surgeon to rule out a possible stitch abscess where a suture is working its way out of your scar line.  Otherwise, I do not see any signs of bottoming out of your implants.  Hope this helps.

Thank you for your question. Please follow up with your plastic surgeon about your concerns as it is difficult to assess from your photos alone. 

In general incisions normally stay red, lumpy and bumpy for six weeks and take six months before they even begin to soften. When concerned always best to be checked by your surgeon.Dr. Ted Eisenberg, Board Certified Plastic Surgeon and Author

HelloIt could be the deep stitches or a suture knot. While it may be early for scar tissue, that is also a possibility. Since you are so early post-op I would wait a few more weeks to allow it to soften up.

Hello and thank you for your question and photo's.   Yes, it can be your deep stitches, perhaps a suture knot, It also can be new scar tissue.  Give it time , you're barely over two weeks post op.

It is not unusual to have feelings such as this at this stage and it does not look like the implants are bottoming out. It is most likely to be related to the stitch line but if you have concerns best for your PS to have a look for you. 

it is not uncommon to get some firmer areas around the internal sutures. you can massage the area and with time, it will most likely soften.david berman md