Baby banging head

Hi! Would like to remain anonymous for this post because it's a sensitive topic.. for me. My son just turned 1 years old. He has the habit of banging his forehead on the playpen gates, or when we're in the car, he likes to stand at the window, look out and suddenly he'll bang his head a few times. We'll immediately stop him. Most of the time it's not hard, but sometimes when he accidentally hits his head hard, he will cry if it's painful. Sometimes he would throw his body back and purposely and repeatedly bang his head to the back when he's frustrated or doesn't get what he wants. But this part, I know this is tantrums. But my concern is the first part, where he bangs his head/forehead on objects, gates. Any of your babies do that? Is it normal? I brought him for his 1 years old immunization and developmental check up at the polyclinic last few days and raised this concern, doctor said to monitor because it's an early sign of ASD 😢 I personally don't think so as he's able to make eye contact with me, interact with me etc. I just feel that.. isn't it too early for the doctor to say all this? The doctor also asked if my son is able to point at objects that he wants, says mummy/daddy or follow one step instructions. I said no.. and I understand and would like my son to take his own time to grow too because he's literally just 1 years old and 5 days. But doctor said she will schedule my son for another appt 3 months later to monitor his language development because it's a concern. Makes me a little sad though. I'm a preschool teacher and I always encourage children to take their own time to learn.. or achieve any milestone because different children develops at different pace. Any of you guys face the same issue? Thank you! 🥺❤️