Breast leakage? ( not pregnant)

5
Hi so recently in the last few months I have noticed some sort of substance in my nipples it's not liquid, nothing is leaking out but it's like a pasty skin color-ish substance. I've seen it in both nipples. I have taken pictures to show my doctor next time. Has this ever happened to anyone? I am not sure how long this has been happening for because to be honest I don't check my nipples at all, I just happened to notice one day. The pasty substance (which reminds me of the benefit pore fessional primer -LOL) has no smell and nothing comes out when I squeeze my nipples ( I have already told my doctor in a previous doctors appointment - at that time I hadn't had any substance in there so therefore I couldn't show her anything). Anyways let me know if this has happened to any of you. ( doctor has done Breast exam on me and found nothing ) I am 22 yrs old btw.