Why didn't he ask for my number?

I met this guy through a mutual friend. We got to know each other through email for the first 2 weeks, exchanged pictures, and he finally asked me to meet up for dinner. We met at this casual restaurant. He gave me a side hug when he first saw me. We sat down and had a really good dinner (he paid), flowing conversation, lots of laughter, and he seemed a little nervous, because he was chatty and shaking his legs a lot. We finished our meal and talked for a while, then he said he had to get going to prep for work. (It was a Thursday night and he's a doctor) We had been together for an hour and a half. So he walked me to my car and said that "we should really do this again sometime." He gave me a front hug and said "I'll talk to you later."

Here's the thing... he didn't ask me for my number and he only has my email address. Does this mean "he's not that into me?" I thought if he liked me, he would have asked for my number.
Updates
+1 y
it's been 6 days since we went on our date and I still haven't heard from him... should i:


forget about him and move on?

or

keep waiting?

or

email him to say hey?
Why didn't he ask for my number?
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