painful lump on breast??

I've never noticed a lump on my breast before but it hurts and I didn't know if this is normal sometimes or what ? I mean it's not big but the only reason I found it was because it hurt in that area and slightly itches. Just not sure what to really think of it or if I'm overreacting or what... 
wasn't sure if it's just from my boobs getting larger all of a sudden or if there could be something wrong. 
Please help..