kinda worried

ok ladies my right boob has been tender but only when I accidentally scrap it against something (usually my arm). while feeling around I felt a really weird for lack of a better word mass. is it normal to develop harder milk ducts if you get pregnant shortly after breastfeeding. my baby is 10 months and stopped breastfeeding at 6 months we have started ttc again and I'm hoping this is our month but I'm still a little ways till af. as I can start anywhere from the 17th to the 26th. I just don't want to worry about it until I have to.