Looks like a zit to me. The opening could be a clogged duct. I had one once in the same area. It healed using a warm washcloth held against it a few times a day for a couple of weeks. Good luck!
Does it easily move around under the skin? I also think it's a zit. Hold a warm wet washcloth over it a couple / few times a day for a week. If that does not diminish or remove it, you probably need to see a doctor.
I do not see anything unusual. If it is the bump just by your thumbnail, that looks like a zit. See if it can be expressed.