Pregnant Megan Fox tells how she is preparing for baby no. 4 (exclusive)

Megan Fox is making sure she’s in the right frame of mind as she settles into her fourth pregnancy.

The Jennifer’s body alum, 38, spoke with PEOPLE about her collaboration with REVOLVE and shared that since announcing she’s expecting her fourth child, her first with fiance Machine Gun Kelly, she’s been making some lifestyle adjustments.

“Since this is baby #4, I’ve already learned all the tricks to making my body feel good physically and mentally,” Fox tells PEOPLE. “I sleep and exercise and stick to my healthy diet and lifestyle, as always.”

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Elsewhere in the interview, Fox shared how her children — sons Noah, 12, Bodhi, 10, and Journey, 8, who she shares with ex-husband Brian Austin Green — reacted to being told they were getting a younger sibling.

“The kids are all super excited about another addition to the family and have promised to help and pitch in,” says Fox.

Last week Kelly, born Colson Baker, commented for the first time since Fox announced she is pregnant with the couple’s first baby together, giving an update on his new music and hinting at the fact that he is soon to be a father again. Kelly is already father to daughter Casie, 15, who he shares with ex Emma Cannon.

In one post on Xformerly known as Twitter, Kelly wrote: “Isolating myself in the desert next week to restart this album from scratch. When inspiration flows through me unblocked we’ll reach the destination in no time. Don’t worry.”

“After all, I’m about to be a father again!” Kelly ended her post sweetly.

Earlier in November, Fox announced the couple’s exciting baby news. The actress cradling her baby bump while covered in black liquid in a Instagram post, and in another snap, she held up a positive pregnancy test for the camera.

“Nothing is ever truly lost. welcome back ,” she captioned the post, using lyrics from Kelly’s track “Last November,” a song about his and Fox’s previous pregnancy losses.