Breast pain can be due to a lot of reasons.
Your description is not enough to reach a conclusive disorder for treatment.
One of the major reasons for breast pain is restrictive clothing. Do check on that.
If you have a breast lump or swelling in your armpit or any discharge from your nipple or generalised redness/ tenderness, please proceed for consultation with a doctor.
Next Steps
The best step would be to visit a doctor for physical breast examination
Health Tips
If you have a swelling in your breast or armpit, please rule out the possibility of Cancer by visiting a doctor.