Updated

A weekend birthday celebration for actress Michelle Williams ended with a trip to the emergency room for Busy Philipps.

“Last night ended super weird… I had a crazy excruciating pain in my lower right side and after a long time at Mass Gen, it was determined my ovary had flipped over- it’s called torsion,” the star, 38, shared on Instagram Sunday morning along with a photo of her with an IV in her arm.

“Mine flipped back by itself and I’m ok but sometimes if it doesn’t you have to get surgery or you can lose your ovary (which actually happened to a really good friend of mine),” she shared.

Philipps said she initially felt like an “idiot” for going to the hospital, but as she explained it was the right decision. “It always is!” she said. “Even if they say you’re fine and send you on your way! And a huge thank you to the amazing doctors and nurses who took care of me!”

Before Philipps’ night took a wrong turn, she shared photos with Williams strolling through the streets of Boston. The pals even wore matching leather jackets with a broken heart that read, “Best Friend.”

A request for comment on Philipps’ condition wasn’t returned.

This article originally appeared in Page Six.