Ah mama, yan ang brown discharge is usually old blood talaga, totally normal! A few of us went through the same thing, kaya don't panic, pero since you're exclusively breastfeeding pa (kahit may solids na), it might take a bit longer before your period fully comes back because of breastfeeding hormones. I'd say keep an eye on it and if it turns red or heavy, or if you're worried, best to check with your OB just to be sure kasi everyone's timeline is different, lalo na with mixed feeding na ngayon!