Help! Something weird is going on with my nipple.

So I'm estimated to be about 7 weeks pregnant since my last period.

I was rubbing my nipples earlier today and I squezed lightly, only to find a think white past come out my nipple.

This is my first pregnancy since my miscarriage 3 years ago, so I'm not quite sure what's going on with my body. Can anyone give me some advice?