From birth, my ebf little boy would go 12-14 days between poos. He too often seemed uncomfortable by day 6 and it would affect his sleep too. When he did poo it was usually creamy like you say - so it is not constipation, just slow transit and that babies use breastmilk very efficiently.
A couple of times we used lactulose that the Dr prescribed when we did think he had constipation, as we did not want to use the suppositories as, as your Dr said the babies can get a dependence on them, I really think you need to listen to your Dr on that. Most of the time we just had to be patient and when he was really uncomfortable (& only after 10 days) we used the lactulose.
Since he started solids at 6 months (he is now 1yo) things have been fine and now he goes at least twice a day
and sometimes lots more... please try not to worry and unless your baby becomes constipated, try and let his body work natuarally - or get some lactulose which is a bit more gentle.
