It is not uncommon for pregnant women to experience rashes on their breasts due to hormonal changes and increased sensitivity of the skin. However, it is always best to consult with your healthcare provider to rule out any potential underlying issues or infections. They can provide an accurate diagnosis and recommend appropriate treatment options if necessary. In the meantime, you can try wearing loose-fitting clothing made from breathable fabrics, avoiding harsh soaps or detergents, and keeping the affected area clean and dry to alleviate discomfort.