ingrown hair outside vagina ??

Sounds exactly like an ingrown hair. The black you see in it could be the hair itself. The way I handle my ingrown hairs is with tweezers, but only if I can actually see the hair. I use the tweezers to gently scrape the skin above the black area, which usually just pops the ingrown hair right up and out of the area it embedded in. If the hair is refusing to come out, you can talk to a doctor who may be able to remove it for you with tweezers or other methods. Popping ingrown hairs usually does no good UNLESS there is an infection around the hair itself. Your body will eventually treat the ingrown hair as a foreign substance and will send in the white blood cells to help "remove" the "infection". "Popping" the area of the ingrown hair at this point could actually relieve the pain as well as remove the ingrown hair itself. Just be sure to clean the area with either baby shampoo or betadine before and after. Don't use harsh alcohols or peroxide down there.
Popping an ingrown hair before any infection has settled in will only result in bleeding, as there is no pus that needs to be evacuated.
So, in the meantime you can either try and remove the hair with tweezers, keep the area clean (but do not overclean). If things get to the point of a pimple-like bump forming, you can either pop it yourself, which may dislodge the hair, or you can go to the doc and he/she will do it for you.