it is okay for your breast to hurt even without a bra on

Breast pain is normal, bra या no bra. it has to do with hormonal changes in your cycle, या just growing pains.

well, there should be a reason for it. Nothing hurts for no reason

That's normal. I am the same way.

As all the others have कहा to some degree its perfectly normal but if it seems to start to do it और than it has या when आप are not expecting it I would talk to someone so for now keep a note of dates when it does it and which side and see if there's any pattern to it. Then if आप are further concerned go and talk to someone start द्वारा talking to your mum या at least a nurse.