Iv a cut under my nail in my tumb. it was cut when i cut my nail the skin came whit it. how long will it take to heal?

Couple days : Different people will heal at different rates . Keep your finger clean and covered if you are dealing with something dirty . Wash your hands regularly . Use gloves. When doing dishes and it will be better in 2-3 days .

Within a week: You should heal rather quickly if you do not acquire a bacterial infection. I would keep the area clean and watch for redness and swelling. If you have redness and swelling see a physician.

Cut under nail : Should heal in a few days unless it is deeper , it will take more than a week. Make sure it is not getting infected. See physician if swollen, tender , with fever pussy.