Uy, one-sided headaches can be tricky, lalo na if you're breastfeeding or pregnant pa lang, definitely better to check with your OB or doctor to make sure it's nothing serious, kasi sometimes hormones and stress from new motherhood can trigger these things but better safe than sorry, di ba? A few of us mums had similar issues and turned out it was just tension from hunching over the baby or sleep deprivation, but your doc can give you peace of mind and recommend what's safe for you and baby. Hang in there, mama!