What happened 😩

Bri • Married and mother to babygirl💓

My daughter used to sleep for 10 hrs uninterrupted since 6 weeks. Now she’ll be 4 months next week and every night she wakes up at 6:30 am like clockwork ( a 5 hr stretch) eat and then go back to sleep for another 5 hrs. What changed ? Is it because she’s teething ?