Hi. Since you say precocious puberty--- how old are you? I'm wondering if the best thing wouldn't be for you to ask your mom about this and perhaps be seen by a doctor. That would be the best thing to help determine what it is. It is difficult from your description for anyone over the internet to tell you what is going on but a doctor can look and diagnose pretty easily. Your mom may also be able to tell you if it is normal, something to worry about, etc. good luck
Could it be ingrown hairs? That's what I'm thinking.
If it's on your bikini line it sounds like irritation. Your underwear may be rubbing the hair folicle causing it to grow inward.