Midwife Nikki replies: Yes, this is normal. Pregnancy hormones make your breasts swell and become tender and tingly early in pregnancy. Yellow ‘colostrum'-your baby's first milk-may start to leak as early as 12 weeks, although everyone's different and some women have hardly any. The reason it happens is that your body is preparing your nipples for breastfeeding-the leaking milk acts as a lubricant and antibacterial. To avoid wet patches on your clothes, wear breast pads from the chemist. Changing them regularly will stop your nipples sticking to them.