On period day 4. right breast randomly started hurting with a soreness/tenderness. only right breast which is larger than left. on bc. no lump felt. near nipple. can pain in only one breast be normal? i usually have breast pain w/ periods?

Right breast pain: Yes, pain in one breast around period time can be normal, but more often the hormonal congestive changes involve both breasts. Absence of a lump is reassuring but if you still have concerns or if the same breast continues to be painful monthly, have a breast examination by your physician, gynecologist or a breast surgeon.

Need to examine: It is not feasible to provide a meaningful opinion without additional history, physical examination and may be some tests. You may wish to watch and wait, if the pain disappears you may address it with your doctor at the next visit. If the pain persists, it would be prudent to see a doctor. Wish you good health!