Arie Luyendyk Jr. and Lauren Burnham -- one of the few couples to have made it from The Bachelor finale to the altar -- opened up this weekend about some devasating personal news:

Lauren recently miscarried the pair's second child.

The husband and wife uploaded a video on YouTube yesterday that detailed their story.

"A little over a month ago, we got the most exciting news and we found out that we were pregnant with our second baby," the video description reads.

"We made so many plans. We bought a new house with more space, we planned how we wanted to tell you all and we envisioned our future with Alessi's little brother/sister.

"We were planning to share our journey through pregnancy with you, but unfortunately we didn't get the happy story we had hoped for."

Said the former Bachelor lead and his spouse:

"We decided to share this part of our journey with you, because well, we share everything with you!

"But also because we hope that by talking about this we can make other couples going through these times a little less lonely.”

The video is 27 minutes in length and opens up on a fun-filled note.

We see Burnham saying that she has “a little secret surprise” and is planning to purcuase two pregnancy tests... sneak them into the bathroom,... mark one as positive ... and arttempt to prank the race car driver, who had accused her of being pregnant because she was “so mean” to him lately.

But then the joked turned out to be on Lauren.

Because one of the tests turned out to actually be positive.

After taking another to confirm it, Burnham, tears in her eyes, says:

“That took a turn that we did not plan for,” turning to the couple's daughter, Alessi, and telling the one-year old: “You’re going to be a big sister.”

Arie Luyendyk Jr. and Lauren Burnham: We Suffered a Miscarriage

From there, after showing an ultrasound to viewers -- in which they learn their eiight-week old fetus is only the size of a five-week old fetus  -- Lauren says that they “didn’t get the best of news."

And her husband says he “is still processing" everything.

After a couple of more doctor visits, the two were given the news of a "missed miscarriage," which happens when the fetus is no longer alive but the body doesn't recognize the pregnancy loss or expel the pregnancy tissue.

As a result, a woman's body may still release hormones and a woman may still continue to experience signs of a pregnancy.

Says Arie:

"It's been a roller coaster of emotions, going from scared a little at first because it was so soon, then happy then stressed and worried for weeks on end, and obviously today was the bad news and it's something you can never prepare for.

"It's been hard holding this back from everybody."

"Trying to pretend like nothing is going on is really difficult," Lauren says in the footage.  "I feel like this is kind of the best way for us to tell the whole story."

Luyendyk proposed to Becca Kufrin on his final episode as the Bachelor -- but then reversed course and asked for Lauren's hand in marriage on the After the Final Rose ceremony in early 2018.

Less than a year later, the reality stars got married in Hawaii.

Please join us in sending them your best wishes during this very difficult time.