Should I message a guy after not talking for a month?

I started talking to this guy I met online (we're both 18+), and after 2 weeks of talking we decided to meet up. He seemed really interested in me when we met up and actually kissed me. But about a week after - we were still talking between the time we met up and a week after - he started to reply to one message and ignore the following one or just leave me on read altogether. I don't know if this is because he's not interested in me or because he thinks I'm not interested in him - as I was nervous when we met up as I really did like him so I may have been quieter than I normally am and he also wanted to progress to more than a kiss but I denied due to personal reasons but I don't know if he took it as I didn't like him. I still can't get him out of my head after nearly a month of not talking. Should I message him or not?

I know I shouldn't rely on guys making the first move and obviously if he doesn't reply then I know he isn't interested, so I should just message him as I have nothing to lose, but I need motivation.

*Guys - what would you think if you were in his position?*
Should I message a guy after not talking for a month?
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