Why do I have no nipples?

Absence of nipples, athelia, is extremely rare and can be seen in some patient's with Poland syndrome.  A more common scenario is that you have inverted nipples that are severe enough that the nipple can not be stimulated to be seen.  An in-person examination with an ASPS board certified plastic surgeon can help diagnosis your situation in order to offer you the best treatment. Best wishes.

the brown spot you are describing is the areola which surrounds the actual nipple. it seems that what you are describing are inverted or hidden nipples. you should see a plastic surgeon for assessment and possible treatment as there are surgical solutions for this. good luck!

Having small nipples or very small nipples is part of the norm and you should not worry.  Know that most of the time with breast feeding the nipples will come out.  In the mean time if you want to correct it you may look into surgery but know that with surgery you may loose the ability to breast feed.  I recommend waiting until you decide if you want to have children or not.