Will this stitch that is sticking out of my right nipple dissolve on its own? (Photos)

It is not uncommon to have sutures come to the surface up to several months after surgery. From your photos, the suture appears to be one that will dssolve. I would call your surgeons office for instructions,however, if that is not feasible, you can safely clip the end, but i would not recommend pullling on it.

If by the 6th to 7th week the stitch sticking out does not fall off like a scab, a surgeon can trim it away.
Dr. Ted Eisenberg, Board Certified Plastic Surgeon and Author

Hello and thank you for posting photos along with your question. The suture appears clear and typically with this surgery most plastic surgeons would use a dissolvable suture so it is very likely a dissolvable suture. However, I think the best course of action is to send them this picture and ask them what you should do. They may allow you to trim the suture so it is not sticking out like it is. Congrats on your recent surgery and I wish you a speedy recovery!Ankur Mehta MD