Hi i have this boil/pimple next to my nipple on my left breast. it started of small and its growing bigger and its becoming yellowish in color with a bit of red. should i be worried?

Doctor can check: Skin lesions (bumps, pimples, etc...) that pop with blood or pus, should be checked by a primary care doctor or a dermatologist (unless it is a tiny typical pimple from a blocked skin gland). Rashes are very hard to describe in words. A diagnosis needs a visual examination, either in person or via a private online consultation (such as HealthTap's consultation service) where a Dr. can look at it.