"It was wildly emotional, physically taxing and truly a post for another day," Tripson, from Florida, wrote on Instagram.
"But it left us with four frozen embryos. Alice Ann was our first. We tried again this past summer with another, but I lost it very early. Two weeks after that, Sam relapsed and three weeks after that, he was gone."
Tripson says while she and Sam didn't talk much about "the end", they did discuss their remaining embryos.
"...I know it's a very personal, private subject, but to us, they were our potential children. On ice. It was always our plan, regardless of what happened, that they would have a chance at life," she wrote.
"Over the past 6 months, there has never been a doubt as to what I was going to do. Even in the ICU during his final hours, I knew what I was going to do. After he was gone, I laid next to him for a long time. I prayed for the strength I would need to get up and leave the hospital and eventually, when I was ready, to move forward with our plans."
According to Tripson, doctors would not proceed with the pregnancy until it was deemed the new widow was "physically and mentally" ready.
"My doctor didn't take this lightly, but he also knew us very well and wasn't surprised by my decision," she explained.
In February, the couple's two final embryos were transferred.
Supported by her mother and her late husband's, Tripson wrote: "There were a lot of tears and so much love in that room. I found out a few weeks later that I was carrying one strong baby. And that's ok. The way I see it, I get one and Sam gets one."
"Of course, it's bittersweet. And yes, a bit unconventional. But it was our decision and what I consider to be one of life's most beautiful blessings."
Due on October 28, Tripson doesn't know if she will be having a girl or a boy.
Speaking to US Weekly she said expects it will be hard to bring her child into the world without her husband, but ultimately she is excited to meet her third "perfect" baby.
"I know this isn't going to be easy," she said. "I'm not scared. I'm so excited to meet this little person. It's hard to process, but just having a chance to meet another one of Sam's children, it just blows my mind."
She said she misses her husband but through her children gets little "reminders of Sam everyday."