Also, I've been soaking my finger in Epsom salt and warm water 2 times a day for the last two days. (I see a small change on the swelling)
It sounds like you might have been poked with something and it got infected. I I would see your doctor. The color change is not good, especially if it is getting black or dark. The only thing you can try at home if it has an opening put 3% hydrogen peroxide and then let dry then triple antibiotic ointment. If that doesn't get better you need to see your doctor. If you see red streaks go to the doctor if they are open or to the ER.
A couple of questions for you are did the fingernail get bent or broken or is it coming up off the nail bed? What color is the finger? Did you injure it? If so how? And how long ago?
Well regardless of how it got like that, it seems that there is an infection.
My advice is to make an appointment to see your doctor who will be able to examine the finger and decide what course of action need to be taken.
Sometimes a boil or abscess may form and this may need lancing and draining. Infections can spread, so it does matter how small it is, it still needs looking at.
As you have asked if it could be in ingrowing nail, I presume that it is on the edge of the finger nail. If that is the case, sometimes we get "back friends", little bits of dry skin and when they are pulled off an infection can occur. Sometimes can just happen. You will need an antibiotic cream to apply to that part of the finger.
Your doctor will decide whether an antibiotic cream will be OK, or whether you need a course of antibiotics.
Thank you all!! I will make an appointment with my dr.