We host a lot of webinars around here, and they are recorded for replay for the most part. Occasionally there is no replay, or it's for a limited time.
Check your webinar confirmation email. We specify whether there will be a replay or not as often as we can.
If you're still not sure, email firstname.lastname@example.org and they'll let you know if there's a replay and whether or not they can get you access to it.