This happens to me all of the time I found some helpful I information
They can be triggered by many causes, including friction, hormonal imbalances, inflammatory disorders, environmental factors, allergies, skin conditions, infections, itching, sensitivity, sexual activity, pregnancy or breastfeeding. Nipple cancer is rare and if both nipples are sore, it’s rarely a sign of breast cancer as that usually only affects one breast at a time.
Known as fissure of the nipple or “jogger’s nipple”, friction from running or other sports can cause nipple pain. Working out without a bra, or wearing a poorly fitted sports bra, can cause soreness by repeated friction of fabric against the skin. Symptoms may include:
Prolonged periods of exercise put you more at risk. Long distance runners are most prone to the condition but other athletes are affected too. Surfers who don’t wear rash guards may also experience this condition.
To prevent friction:
Always wear a well-fitted sports bra
Use synthetic fabrics rather than cotton
Wear a waterproof plaster or surgical tape during exercise
Use customised protective products, like rash guards
If skin is already damaged use nipple shields or apply a barrier cream.
Seek medical advice if concerned.