Sore red bump/spot/nipple like on aerola next to nipple on right breast, could it be a pregnancy sign or something seriouse?

Several posibilities: Go see a doctor and show them the lesion and let them examine you and arrive at a diagnosis. Probably nothing serious, but never hurts to make sure.

Infection probably: That's not a common sign of pregnancy. It could represent inflammation or infection of hair follicle or sebaceous gland. Need to be checked and examined by your gynecologist.

Montgomery Glands: What you are describing sounds like montgomery gland cysts. These are modified oil glands that lubricate the nipple and have a tendency to get blocked and inflamed. If this doesn't improve over the next few weeks, please see your gynecologist to make sure all is well.