Is this normal?

When my LO was born he was a poop factory. I laughed at how often he pooped. When he turned 8weeks old he just stopped. My husband and I are confused to say the least. LO eats 8-10 times a day and only poops maybe once a week. He doesn't seem upset by his lack of poops and has lots more farts now. I asked the np and she said since he's breastfed not to worry about it. That he will poop eventually. So is this normal? Should I worry? Mix prune juice with his milk bottle?

Edit: thanks for all the reassurances!