Couple Documenting 'Challenges' of Fertility Journey Has 3 Embryos Left But Says, 'This Is Not the End of Our Story' (Exclusive)

“Infertility can test a marriage in unimaginable ways, but it can also strengthen your bond,” Kristine Sheriff tells PEOPLE

• Kristine and Dan Sheriff are high school sweethearts who've been together for 18 years

• The pair have been open about their fertility journey — including Kristine's PCOS — on TikTok

• Kristine says despite some setbacks along the way, "this is not the end of our story"

Kristine Sheriff and her husband, Dan, have been sharing their fertility journey online, and they’ve admitted it hasn’t been easy.

The couple met when they were high schoolers and started dating when they were 17. Dan asked her to be his date to their senior prom and she recounts that “three days later,” they were officially a couple.

Despite being together since they were 17 and recently renewing their vows for their 10-year anniversary, they’ve struggled with infertility. Kristine, 35, was diagnosed with polycystic ovary syndrome, or PCOS, at 19; this hormonal condition makes it difficult for a woman to conceive and carry a child to term.

“Over the next few years, we weren’t actively trying to conceive, but we also weren’t doing much to prevent it,” Kristine admits to PEOPLE. “At 25, the summer before our wedding in 2014, we officially began trying to grow our family. We faced difficulties early on and, after some time trying naturally, realized medical intervention would be necessary.”

Kristine recounts how only nine of the 27 eggs they first retrieved managed to successfully fertilize and freeze. One of the two embryos was successfully implanted after their second attempt in November 2021, but unfortunately their “Christmas miracle” was short lived.

Related: Couple Decides to 'Close Shop' After 10-Year Infertility Journey. One Month Later, They Get Huge Surprise (Exclusive)

“In January 2021, we miscarried on the same day we heard the baby’s heartbeat,” she says. “[It was] a devastating loss that required time to heal.”

Since her miscarriage, Kristine has taken some time to try and tackle her PCOS symptoms by undergoing weight loss surgery. She shared her journey to losing almost 100 lbs. online, and once she and Dan were ready to try again, she decided to start sharing her fertility story with her TikTok followers.

“I had already received tremendous support while documenting my weight loss journey, so I decided to open up about our experience with infertility as well,” Kristine shares.

According to the World Health Organization, around one in six people around the world struggle with infertility, and PCOS is the leading cause of infertility in women. Lifestyle changes (including weight loss) are part of the treatment options for PCOS, especially for those looking to increase their chances of getting pregnant.

“In our third transfer attempt, we were hopeful that my weight loss would make a difference, but unfortunately, neither of the two embryos implanted,” Kristine continues. “Despite the ups and downs, we remain hopeful and are exploring our next steps with our medical team.”

Before attempting their next transfer, the couple renewed their vows in Ireland for their 10-year wedding anniversary. The pair currently have three frozen embryos left, and they’re hoping they “brought the luck of the Irish back home” as they prepare for the next transfer.

Related: 12 Celebrities on Dealing with Infertility

“Infertility can test a marriage in unimaginable ways, but it can also strengthen your bond and deepen your love for one another,” Kristine says. “Facing these challenges together has made us more resilient and more united than ever. I’m beyond grateful for [Dan’s] steady love, and no matter what happens, I’m beyond blessed in this lifetime because of him.”

“We’ve learned to hold space for hope, grief, joy and even humor in the moments we can find it ... Even when life takes a different path than planned, there is strength in love, and we’re committed to walking this journey hand in hand. This is not the end of our story — only a chapter.”