Halli Makennah Chris Lane and Lauren Bushnell Lane

And then there were three!

Chris Lane and Lauren Bushnell Lane welcomed their first baby, son Dutton Walker Lane, on Tuesday, June 8 in Nashville, Tennessee, they confirm to PEOPLE exclusively.

Born at 11:12 a.m., Dutton weighed in at 9 lbs. and measured 19.5 inches long.

“Everyone in the room, including Lauren and me, were shocked we had a 9-pound baby! Not sure where he was hiding in her belly?!” the country singer, 36, jokes to PEOPLE. On a more serious note, “Watching Lauren go through the birthing process – from the beginning to the moment she delivered – was the most incredible thing I’ve ever witnessed. I experienced an emotion I’ve never felt before.”

Adds Lauren, 31: “I’ve never felt an immediate unconditional love like I now have for Dutton. And going through this experience with Chris has made me love and appreciate him even more … I didn’t think that was possible!”

lauren lane/instagram Chris and Dutton Lane

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And much like his hit “Big, Big Plans” was written for his proposal to his now-wife, Chris has also penned a new tune for his newborn son.

“I’ve been waiting to meet Dutton for nine months now, and the easiest way for me personally to describe my feelings and emotions is to write about it! So naturally, I wrote a song,” he tells PEOPLE. “It’s called ‘Ain’t Even Met You Yet’ and sums up how I’ve been feeling over the last few months. I can’t wait to share it with him one day.”

The couple announced their pregnancy news in December, sharing a video of an ultrasound of their baby on Instagram. “It was very exciting but now feels even more real seeing the ultrasound and hearing the heartbeat,” she exclusively told PEOPLE of the news at the time. “We are just soaking it all in!”

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The former reality star documented her pregnancy journey on Instagram, sharing baby bump photos along the way and opening up about not comparing her progress to other moms.

“Pregnancy is amazing! Reminder to not compare yourself to others,” the Bachelor alum wrote on Instagram in February. “This is my belly but everyone’s looks different! I have compared myself to friends who are about as far along as me or have been pregnant before and worried that maybe my belly or baby was too big for my gestation and for it being my first.”

“But I have to remind myself everyone is different. Everyone’s bodies are different and every baby is different but all are so beautiful!” Lauren added.

In a candid New Year’s Day blog post, Lauren shared that, while “it didn’t take us an abnormal amount of time, the whole process really opened my eyes to the struggle that many women and families face.”

“On October 25th 2019, Chris and I married and although we were excited to start a family, we decided we wanted to enjoy some time together before trying for [a] baby,” she wrote, noting that she ended up going off birth control in March 2020. “I wasn’t necessarily feeling rushed, but it was definitely something that both of us wanted and felt very ready for.”

Lauren Bushnell/Instagram

However, “after four to five months of trying,” Lauren wrote that “worry started to enter my mind.”

“I couldn’t help but compare my situation with those of my friends who it happened very easily for, a lot of the time unplanned. Mentally, this was a really hard part of the journey,” she shared. “I’m not sure if other people have experienced this, but as a woman, I assumed there was something wrong with me. Chris would see how disappointed and worried I would get and I could tell he felt really bad.”

“And as hard as trying to conceive is on the woman, I just want to take a moment to acknowledge the impact it has on husbands as well. I’m so thankful for Chris. He is such an eternal optimist and I admire his faith so much – he truly was my rock through the emotional rollercoaster of it all,” she added.

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Starting in July, Lauren said she began using ovulation strips and at-home progesterone tests – and then in September, the couple got the happy news they had been waiting for.

“As I write this I am so incredibly thankful to be pregnant, but I simultaneously can’t stop thinking about all the women out there who have experienced a much longer struggle than I ever did and are dealing with infertility and pregnancy loss,” she added.

“Pregnancy truly is a miracle and I’ll never take that for granted. We prayed every day for months and obviously our prayer was answered, but I know there are a lot of unanswered prayers out there,” Lauren said. “So many women who are quietly struggling and I’m thinking about every single one of you. I pray for hope and peace for everyone reading this struggling. Miracles happen every single day.”