Great job keeping your chin up and your efforts going as you learn the patterns in your area.
We have found a couple weeks before and after the new school year begins slow and also a couple weeks before Christmas. We've had events where no one has shown and those hosting the event ended up being the participants. Those were some good times though, bringing the team closer together, and helping us to relax and remember to explore these events ourselves.
We've also had events where those who RSVP'd brought last minute friends and we had drop ins so we ended up with a large group. Depending on the theme, those can keep the hosts hopping and you don't have the same connection that is found within smaller groups.
Sometimes you can't predict what the weather will be, sicknesses going around, and just have to go with the flow.
Have fun with the Chemistry event.