Girls, I'm asking for advice from you. My son is 3 and wakes up every …

Girls, I'm asking for advice from you. My son is 3 and wakes up every other night around 21:30-22:00, then he wakes up at 1:00, then at 3:30-4:00 and may not sleep until 7:00 in the morning. Then he might fall asleep 1 or 2 times for 2-3 hours, and the rest of the time he sleeps for 10-15 minutes. Is this normal? And also, when he doesn't sleep, he spends more time on his stomach, is that normal?