Suggest Remedies For A Brown Spot On My Face While Breastfeeding

Hi I am 30 years old and have a four month baby and I am breast feeding. My problem is on my face I used to have a little brawn spot that becomes bigger when I gate pregnant. Now I need to clear out or lighting it, but I do not know what product I have to use and I want to make sure if it is safe with the breast feeding .