Constipation in 2 month old ?

I need some input from other mommas. My son is 7 weeks today, 2 months next week. He hasn't pooped since Friday night. He's being normal other than that. I called his doctor and he told me they don't really worry about it as long as he doesn't have any other symptoms like not eating or having wet diapers as much. He said it happens because around this time they start absorbing all the milk and they don't poop like before, just once or twice per week. Exclusively breastfed here. Now they told me I could give him some juice to help him get things moving in there, but that at the same time it could cause diarrea if he's not constipated. I'm so used to him pooping all the time that I feel like this is not normal. Did this happened to you? How much does your breastfeeding baby poops now? I don't know if I should just wait it out!