Ay, totally normal yan, mama! A few of us mums experienced the same thing around 4 months, the yellow, thick discharge usually comes from hormonal changes while breastfeeding, kaya kahit gaano katagal kami nag-breastfeed, parang di kami bumalik sa normal agad. Long as walang foul smell or itching, and parang mucus lang talaga (not bloody), most of the time it's just your body adjusting pa. That said, some mums had yeast infections around that time din na similar lang ang symptoms, so if it starts to smell off or you feel itchy, better get it checked with your OB just to be safe, basta para may peace of mind ka agad.