If you buy Pro (from the official site) for 6 months, you're entitled to tech support & free updates for 6 months. Likewise if you bought Pro for 12 months. ..benefits expire after 12 months.

You said "It's been a long time ago since the purchase"...how long? Check your CC statement for when you bought Pro...who is the vendor that shows up next to your payment?

Pro doesn't even cost $39 now...if you paid $39 a long time ago then you must've bought Pro from a scam site.
Some scam sites can rediredt you to the official site to download Pro, once you've paid. But that doesn't mean that you've bought from the official site.