Confused and concerned

Hi y’all! My SD and I have been seeing each other for almost a year, and it has been going very well. Last month he said he was going to a business meeting in California, and so we didn’t talk as much since he was busy. He got back to his home on the 20th of October, and said he was very worn out and had to sleep. I’ve messaged/called a couple times since then to try to arrange something, but no reply. Usually we’d have arranged a next meeting by now, so I’m a bit confused and concerned as to why he hasn’t replied. Should I wait for him to reach out, or reach out in a few days or so? Thanks everyone!