13+weeks pregnant: changes in breasts

I am 20 years old, 13+weeks pregnant, my first pregnancy. I am just entering my 2nd trimester. I am now showing with a cute little baby bump. My CM is creamy, a heavy vaginal discharge, pads are now a daily frequent nessesity. I now have a cute little tummy that seems to get a bit larger everyday now. I'm not sure if that's my imagination or not? And my breasts have changed. I have already gone up a full cup, from 32A to a 32B. I already need and have bought new bras. Both my breasts and nipples are extremely!! sensitive. My bf at times doesn't quite realize how sensitive they are especially while we are in bed, having sex. My nipples have darkened a little and my areola's seem also to have changed. When my nipples are pinched they produce a small amount of, I suppose milk? Just a little.... Am I already lactating? Or is my body preparing me for lactation? I'm now just imagining how big my boobs will get, how large my tummy in the next following months?