Newborn is constipated

So my 3 week old has been constipated for the last 2 days. He’s only had about 1 food stool a day but plenty of pee filled diapers. We tried the gripe water yesterday which is how we got him to pass the 1 stool, but we have given him 2 more does since yesterday and no stool. What other things can we do to help him along? Should I call the dr? We’ve tried tummy massages and the leg pushes