If you missed ordering the 20th V-Pet don't worry...
You'll have another chance, because Bandai has opened up a second wave of ordering.
Details are the same, except this new wave will ship in July. The end date for orders is the original date (prior to them selling out of the original allotment) of March 27th. They may end up selling out early again, so you may not want to wait until the last minute.
Price is the same as 3,780 yen at the Premium Bandai store.
We'll keep the prior discussion thread open for now, so head on over there to talk about the 20th V-Pet and I'll be updating the news there also.
Details and help with intermediaries can also be found in the prior thread.
Thanks to nunemon94 for the heads up.