Breast pain and tenderness during pregnancy can happen for different reasons, some quite normal as your body changes, but a sharp pain is worth paying attention to rather than just waiting it out. It could be something like ligament stretching or just the breast tissue growing, but it could also be something that needs a proper check. I would suggest mentioning it to your gynae or PD at your next visit, or sooner if the pain is intense or comes with other symptoms, just to be safe. Better to get it looked at and have peace of mind than to wonder.