What Causes Black Spot In Nipple?

Hello, when I have in the shower today I noticed to black spot in my nipple, I squeezed it and a little bit of black came out( was like how a blackhead comes out on up your face when you squeeze it.) I am so worried I have cancer or something. I have put fake tan on twice this week is this causing it please help.


I'm 18 and me and my boyfriend are very sexually active and he tends to kiss and suck my nipples, has this caused it ?