Baby wakes at the exact same time every night

My baby goes to bed around 7:30pm and consistently wakes up around 12:30am and 4:30am every night. I pause for about 3 minutes whenever he wakes up, but he continues to cry so I always nurse him and he immediately goes back to bed. Is this normal to wake habitually at the same time every night? I’m worried that I’ve gotten him accustomed to this schedule, but I hate to let him cry it out much longer than a few minutes.