need help with baby sleeping?

Kayley • Hey everyone, I am 20 years old, baby boy named Zayden💙
My son is 4 months old and he usually sleeps quite good, going to bed at 7-8pm till 7-8am and only waking at 4ish for a feed. But the last few days, he's been waking up at 5/6 o'clock, and I'm absolutely exhausted💤 any idea why my son is doing this? He used to sleep longer.