lol @Vampire
Sometime IGG doesn't announce that there is 2xp. We have to figure it out on our own when there is no announcement.
They did this quite a few times already when theres no announcement of 2xp event but it is actually turned on. Best way to check if theres 2xp is to burst with a cow.
If you cow gained 4 lvl from 2 beetles then its definitely 2xp. If not then all well.

A lot of people miss out on the event simply because they didnt bother checking for 2xp by doing the cow lvling method.