Think you might be pregnant? On July 6th, you can find out for sure at art gallery Proteus Gowanus in Brooklyn.

All you'll have to do is inject your urine into a frog. Cool?

You see, in 1933, biologists discovered that if they injected the dorsal lymph sac of an African clawed frog with the urine of a pregnant woman, the frog would lay 100-200 eggs. (It has to do with a chemical particular to pregnant women's urine, human chorionic gonadotropin, or hCG.) The practice became a popular form of pregnancy test and frogs were imported from South Africa across Europe and to the United States.

And before frogs, it was mice and rabbits. From Slate:

In the late 1920s, a German chemist, Selmar Aschheim, teamed up with a gynecologist, Bernhard Zondek, to develop the first of these procedures, called the "A-Z test." The doctors would repeatedly inject five female mice with a woman's urine over several days. Then they'd kill the mice, dissect them, and examine their ovaries—enlarged or congested specimens would signal a pregnancy. Within a few years a slightly better test was developed; it used rabbits.

As simpler, less-live-animal methods of determining pregnancy were developed, the use of frogs, mice and rabbits largely died out by the 1960s.

But leave it to nostalgia-happy Brooklyn to bring it back. From the listing on Brokelyn:

Free pregnancy tests will be performed in the Proteus Gowanus gallery on Friday, July 6th. We will also share some simple laboratory skills. Frogs will be given awayfree to good homes who are ready to use knowledge of this Do-It-Yourself test. No permanent harm is done to the frogs in testing and they can be reused multiple times.

According to anthropologist and CUNY professor Eben Kirksey, the exhibition is about "looking at culture in context of all species we share planet with." It's also about raising awareness of how the tradition may have wiped out different frog species. The African clawed frog acquires a fungus as a result of the test, and although they are immune, they can give it to other species of frogs, which can lead to "amphibian mass extinction."

"It's about the implications of new biotech. No one knew in the 1930s that they'd be spreading this fungus," Kirksey told Metro. "So, if this has resulted in mass extinction, what are the new biotech schemes doing?"

"The DIY Frog Pregnancy Test" is at Proteus Gowanus, 543 Union Street. Exhibit starts Friday July 6th at 7PM.