What Causes Discharge Of Clear Liquid From Breast After Miscarriage?

Hello! I had miscarriage on Saturday evening, I was 11 weeks and 2 days pregnant. There is some clear liquid comming out of my breasts since Sunday. Is that normal after miscarriage? And my blood group is rhesus negative, but my partner is rhesus positive, I asked for anti d injeciton, but here in UK they dont give it if the pregnancy is less than 12 weeks.