It's either go time or condom time.

If you’re , this weekend is basically your Superbowl. That's right: December 11th—yes, Sunday—is the most fertile day of the year, according to home pregnancy test manufacturer e.p.t.

The company looked at national birth records and determined that the most popular birthday in the country is September 16th. Count back nine months and you’re lookin’ at December 11th as the date most of these babies were likely conceived, assuming they were born on their due dates.

However, whether you want to blame it on holiday fever or proposal season, it looks like not all of those pregnancies were exactly planned. After across the country, e.p.t also found out that 45 percent of women said their pregnancies were unplanned—a number that correlates with national data on unplanned pregnancies from the Centers for Disease Control and Prevention.

On top of that, nearly 40 percent of women said they were more scared than excited to find out whether they were pregnant (only 30 percent said the opposite), and 55 percent of women who weren’t pregnant were relieved to find out that they didn’t have a bun in the oven. And while 80 percent of women said they found out they were pregnant from a home pregnancy test, only about half said they took the test right after they bought it.