Constipated baby

Hi

My daughter is 5 months old. M giving her solids every other day and she doesn’t eat much. Hardly 0.25oz. And other than that I breastfeed her, no formula at all. But it’s been a week she has had a bowel movement. I tried prune puree but it didn’t work. What else can I do? I call her pediatrician and they said baby can go for 7 days without pooping. This has never happened before. Have you ever been in this situation? When should I go and see her doctor?

TIA