"Maks and I were so careful, but one night we weren't," Peta Murgatroyd tells Fit Pregnancy and Baby for its June cover story of her surprise announcement

Credit: Silja Magg/Fit Pregnancy

First-time parents like Peta Murgatroyd know that handling a newborn baby can be pretty scary at first.

In her cover story for Fit Pregnancy and Baby, the new mom — who brought along son Shai Aleksander, 4 months, for the shoot! — admits there were certain tasks she was hesitant to take on by herself during those initial few weeks of parenthood.

“At first, I had no idea what I was doing. I’d never even held a newborn before. I was nervous, and I didn’t want to make any mistakes,” says the Dancing with the Stars pro. “I tried to give Shai a bath and he was so slippery, I felt like I was going to drop him, so I had my nanny do it for weeks.”

Adds Murgatroyd, 30, “She’s a godsend. She said, ‘You’ll do it when you’re ready.’ And eventually I did. Now his bathtime is one of my favorite times of the day.”

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Credit: Silja Magg/Fit Pregnancy

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Luckily for Murgatroyd, she didn’t have trouble with Shai latching on to breastfeed (he did so “right away”). However, there was one side effect of the process she wasn’t expecting.

“What they don’t tell you is when breast milk comes in, your boobs go rock-hard. That was super painful!” she says. “I had [fiancé Maks Chmerkovskiy] in the shower with me, massaging my boobs. My nipples were bleeding too.”

“But now, breastfeeding is totally fine. I even look forward to pumping,” Murgatroyd shares. “I write notes on my phone, watch videos, plan my choreography. The only funny part is my left boob no longer produces anything. All the milk comes from my right boob. Everybody at work knows I’ve got one big boob. It’s hysterical.”

The closeness between the couple is no surprise, considering their longtime companionship. Murgatroyd shares that the twosome will tie the knot in July at a Long Island, New York, castle, with Murgatroyd’s mother carrying Shai down the aisle and the baby boy joining the couple on their honeymoon.

Credit: Silja Magg/Fit Pregnancy

The professional dancer may be partly well known for her amazing figure, but she confesses that getting back into her DWTS shape definitely took some time.

“I still looked five months pregnant right after I gave birth,” she says. “A friend who came to the hospital said, ‘Oh, you sure there’s not another one in there?’ I laughed, then went into the bathroom and cried. I’d just had this beautiful kid. I was high on life. That was a joke that I didn’t need to hear.”

The new relationship Murgatroyd had with her physique didn’t disappear when she left the hospital. “Back home, I didn’t recognize my body. I had massive DDD boobs. It was overwhelming.”

“So I posted a selfie on Instagram as a way to reach out to other women. I’m a dancer who is usually pretty damn fit, and I looked like a different person. Now I know you have to give yourself time.”

Credit: Silja Magg/Fit Pregnancy

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Murgatroyd expands a bit on the reason she and Chmerkovskiy, 37, decided to wait a little while before introducing their son to the public.

“When Shai was 11 days old, he got a fever and we took him to the hospital, where he stayed for two days,” she recalls. “He had a bacterial infection. That experience made me more fearful. Our house went into lockdown.”

She adds, “We put a Purell dispenser at every door and allowed only family to see him. No friends. Having visitors can feel overwhelming anyway. And I wanted Shai to myself for a while.”

Credit: Silja Magg/Courtesy Fit Pregnancy

The new addition into the couple’s lives, Murgatroyd admits, was a surprise — “Maks and I were so careful, but one night we weren’t,” she says — but she couldn’t imagine their situation any other way now.

“I was induced at 40 weeks, because they thought Shai was going to be too big. [He was 7 pounds, 11 ounces.] My plan was to give birth naturally. But my doctor warned me that induction would hurt, so I got an epidural,” she explains.

“Sometime during the night, my water broke. I pushed for 30 minutes and he was here!” Murgatroyd continues. “Suddenly my baby was on my chest. Maks and I were in shock for the first 30 seconds.”

“Then Maks started to cry, and then I did too. Shai looked at me, took his first breath, and just made a little noise. It was the best day of my life.”