White discharge during pregnancy is normal... It's called Leukorrhea. It's too keep the birth canal and cervix safe from infections. It starts at about 6-8 weeks and continues throughout the pregnancy, increasing as the weeks fly by. As long as the discharge has no foul odor or appears to be yellow or any other color it's fine.
I've had it since I found out I was pregnant which was around 4 weeks. And I still have it, just got heavier. Some ladies it goes away, some it stays consistent or get a heavier like mine. Just varies by body. I had to get longer pantiliners now because there's so much. BTW I'm 22 weeks.