Leaking nipples...

Can you girls tell me more about it? I star notice this like last week, now I'm 15+4. How to stop this? It dries in to my bra and the feeling is not the best when I have to take My bra off :( one of my nipples starts bleeding after that , but just a little dots... Because it stucks to my bra.. what to do? Is it not dangerous? Why doctors didn't tell me anything on my first two appointments :/