it regenerates based on gifts added to the site(to clarify not by you by everybody)

for more details just try to enter something without enough points, it'll tell you

It automatically refills after a while, just need to wait a while and you should have more points.

So, you've entered 2 giveaways, and have 2p left? o.O

You DID look at the FAQ? Well STRANGE, cause FAQ says this:

New users start out with 25P. Every time anyone submits a game, every member of the site, excluding the giveaway creator, receives 5 percent of that gifts value (in USD) in points. For example, if a $50 gift is created, every user on the site receives 2.5 points. And, if a $20 gift is created, everyone would receive 1 point. These points can then be spent on entering giveaways.