LO's lip is bluish. HELP!!!

mga momsh, breastfeeding mom here. Parang bruise. Is this normal po kay baby? kaka 1 month lang po nya and kanina ko lang po ito napansin. She doesn't seem bothered naman po kasi di naman sha nag iiyak and still latching well. Naisip ko lang baka sa prolonged sucking nya, minsan kasi matagal sha matapos dumede. Worried lang po.. sana may makasagot and mka advise. ? TIA