Constipation help!

I’m obviously calling the doctor- but hoping someone has tried and true safe remedies.

5.5 month old started solids eating peas and green beans and then became constipated on the 4th day and hasn’t pooped in several days. Baby’s not bothered at all, thankfully

Is this normal? What did you do? He’s on breast milk only. I stopped feeding foods at this point to see, but still nothing.

(Please no opinions on when to start or not start food, just looking for help with regulating baby)