Fake registrations for Zoom meeting with private invitations?

I host small, invitation-only events for women professionals via Zoom. I've been doing it for months. Suddenly, after I invited 3 people to a new event last Friday, I've received two registrations from email addresses that look fake, with male names. I emailed them to ask if we'd spoken before, but no response from either.

I'm concerned for two reasons:
- First, I have no idea how they got access to the invite/registration link in the first place. I'm 99% sure it wasn't through anyone I sent it to. Do they have access to my Zoom account?

- What other information can they access, or are they phishing for?

Thanks for any help!