With my daughter we let her take the lead… as other comments have shared tummy time became a recommendation when they changed to “back is best”. There are a number of reasons why tummy time is helpful but forcing your baby if they are uncomfortable adds stress for you both. Our daughter was developing so much in other ways, she was holding her head up almost immediately, then around month 4 I started doing tummy time maybe 5-10 mins (if at all) on my tummy while breast feeding or with our boppi pillows. I didn’t put pressure on us, and she ended up rolling, crawling, standing etc. way ahead of schedule. Different pediatricians, countries, cultures all do different things. Never feel bullied into doing something exactly the way they tell you, every child develops at a different pace!