I have had small lumps that ended up going away from breastfeeding. Wishing you the best!
It can be a cloged milk duct in your breast, you sometimes get them while your pregnant as your body is getting ready to breast feed (even in early stages of pregnancy) although they are more common once you actually start breastfeeding and can be painful when your ilk comes in! Good luck and keep us posted!
I am still breastfeeding my 14 month old son and in the process of weaning him so that may be the reason.