Nipple sensitivity(maybe tmi)

Well lately my nipples and almost my entire breasts have been really sore and sensitive. I haven't thought anything of it except that its annoying especially when my boyfriend so much as touches them. But last night a friend of mine suggested it could be mastitis cuz she spoke to someone who had the same random sensitivity and pain and thats what it turned out to be. Honestly it is a constant thing and there arent any lumps or anything so should i worry and call my doctor? I just feel like its something that just happens.