Sarah Herron is reflecting on a heartbreaking experience.

A year after The Bachelor alum gave birth to their late son Oliver at 24 weeks, she explained how his death has impacted her pregnancy with her and husband Dylan Brown's twin daughters.

"The morning we found out we were losing Oliver, a friend of mine who'd been through loss encouraged me to take as many photos and videos as I could in our final hours of pregnancy," the 37-year-old wrote on Instagram Feb. 12. "Still to this day I'm stunned that they're some of the only videos I have of me pregnant with Oliver. I guess it just never occurred to me to take videos in happier times."

"I've been careful in this pregnancy not to let myself get 'too attached too soon,'" Sarah, who has been candid about her IVF journey, continued. "I've been wearing baggier clothing, hibernating and denying when friends ask me on the phone if I'm starting to show yet. Even in subsequent pregnancy I *still* find myself limiting my exposure to other women's pregnancies—even my own."

Understandably, it's an uncharted place. "Pregnancy after loss is just a whole new, complicated territory," she continued, "and I wish there was a playbook."

Though she struggled to share the highs alongside her lows, she's learned to embrace what her new journey holds.

"When I got out of the shower the other day, and caught my reflection, there was no denying that there are two beautiful little girls growing inside my belly," she noted. "So while part of me saying ‘play it safe, don't go there yet' there's another part of me, a more authentic part of me that's saying ‘This is happening. It's ok to let yourself enjoy it.'"

Last February, Sarah shared her son Oliver had died after she gave birth at 24 weeks pregnant. 

"There are no words for the magnitude of loss and pain we're experiencing," she wrote at the time. "It's beautiful and simultaneously tragic. He had my nose and his dad's mouth and long fingers."

A year later, the tragedy still felt like just yesterday. 

"It's been 1 year of soul-awakening grief and rebirth," she wrote while celebrating his birthday Jan. 28. "It's been the longest and fastest year of my life; unbearable and becoming."

"I promise your name will always be said in our home and your sisters will know all about you," she continued. "I hope they have your little nose and dad's long arms but I know that they will never be YOU. We love and miss you forever, Oliver."