She and her kids have tracked the growth of their newest family member, a boy, by comparing his length in the womb to everything from a Target receipt to Amazon boxes.

17 inches, y’all. This baby is 17 inches long, and he finally dropped further down so I can breathe again! ?????? . And sadly, we live over an hour from the nearest Target! So, we pretty much have to turn it into a day trip every time we go...which is a great excuse to buy everything in the store, am I right? ????????? . SIX MORE WEEKS. ??

A post shared by Charlotte Chatman (@cbchatman) on Jul 26, 2018 at 9:04am PDT

A shortened list of things that made me irrationally upset this week: . -the amount of garlic in spaghetti sauce -a Walmart Grocery ad -my husband’s opinion on pumpkin scented candles -why flat irons only last one year -trying to find pants that fit -people . So, yeah, let’s stick to Amazon for the next month because you do not want to run into my crazy, pantless self out in public right now. ????

A post shared by Charlotte Chatman (@cbchatman) on Aug 3, 2018 at 6:31am PDT

Chatman, 28, started the photo series as a way to document her fourth pregnancy for friends and family across the country.

\"PHOTO:
Charlotte Chatman
PHOTO: Charlotte Chatman poses with her husband and their three children.
>

“My husband is a Navy pilot so we’ve spent pretty much every birthday, holiday, milestone away from our families -- and pictures are how we stay in touch and share everything,” she said. “After four years of doing that, you just learn to get pretty creative.”

Chatman used a letter board for the first time with this pregnancy and made it an educational and creative experience for her kids, ages 6, 2 and 1.

Baby kicks: my favorite and least favorite parts of pregnancy. ?? We’re at the point where this kid feels like a shark violently trying to stick his fin to the surface, and I’m half-amazed every time...and half-excited to only have 8 weeks left of my insides being beaten up all day. I’m thinking of doing weekly letterboards until Leif is born; what do you think? Yes? No? Also, this baby shark song. Who wrote it? Are they millionaires now? Why didn’t I think of it?? Why are my kids so obsessed with it?? It’s like seriously two words REPEATED OVER AND OVER AGAIN. ??????????? . . Anddd I’ve been living in this buttery soft maternity skirt by @shoppinkblush ?? #shoppinkblush #prettyinpinkblush

A post shared by Charlotte Chatman (@cbchatman) on Jul 12, 2018 at 11:47am PDT

“As we make the letter board, they call out the letters,” she said. “All the props are stuff they make together as art projects.”

The photos are also a creative outlet for Chapman, who was a musician before becoming a full-time mom.

“I had a lot of creative outlets before I had kids but once you have kids you kind of have to change everything,” she said. “I don’t have a way to pick up hobbies so pictures have been my outlet.”

","canonicalUrl":"https://abcnews.com/GMA/Family/mom-channels-britney-spears-document-4th-pregnancy/story?id=57058209","legacySlug":"/family/story/mom-channels-britney-spears-document-4th-pregnancy-57058209","noIndexNoFollow":false},"publishTime":"18:24","publishDate":"08-06-2018","updatedTime":"20:01","updatedDate":"08-06-2018","socialImage":{"alt":"Charlotte Chatman, of North Carolina, channeled Britney Spears in a photo documenting her fourth pregnancy.","credit":"Charlotte Chatman","ratio":"16x9","url":"https://s.abcnews.com/images/GMA/pregnany4-ht-mem-180806_hpMain_16x9_1600.jpg","width":992,"height":558},"datePublished":"8/6/2018 18:24:00 GMT","video":{"live":false,"id":57058209,"headline":"Mom's funny messages document her pregnancy","mediaAssetTitle":"GMA_Mom documents pregnancy with humor_180806","description":"Charlotte Chatman's Instagram posts are a viral hit.","duration":"0:52","posterImg":{"url":"https://s.abcnews.com/images/GMA/default-img-undefined.png","width":608,"height":342},"video":{"feed":"https://service-pkgabcnews.akamaized.net/opp/hls/abcnews/2018/08/180806_gma_digital_BritneyMom1_,500,800,1200,1800,2500,3200,4500,.mp4.csmil/playlist.m3u8"},"playlist":["56917519","57011186","56986784"]},"relatedItems":[{"contentType":"story","date":"August 3, 2018","headline":"Your kid will probably be invited to a 50-50 birthday party this year ","section":"family","slug":"/family/story/kid-invited-50-50-birthday-party-year-56917519","id":56917519,"image":{"alt":"Your kid will probably be invited to a 50-50 birthday party this year ","url":"https://s.abcnews.com/images/Lifestyle/birthday-party-gty-jpo-180531_hpMain_4x3t_240.jpg","credit":"STOCK PHOTO/Getty Images","ratio":"1x1"}},{"contentType":"story","date":"August 3, 2018","headline":"This infant dressed as female icons is your daily dose of girl power","section":"family","slug":"/family/story/infant-dressed-female-icons-daily-dose-girl-power-57011186","id":57011186,"image":{"alt":"This infant dressed as female icons is your daily dose of girl power","url":"https://s.abcnews.com/images/GMA/inspiring-women-baby-shoot-jackie-o-ht-jef-180803_hpMain_4x3t_240.jpg","credit":"Jenelle Wexler|Getty Images","ratio":"1x1"}},{"contentType":"story","date":"August 6, 2018","headline":"This mom created a genius solution for women to deal with breast milk while traveling","section":"family","slug":"/family/story/mom-created-genius-solution-women-deal-breast-milk-56986784","id":56986784,"image":{"alt":"This mom created a genius solution for women to deal with breast milk while traveling","url":"https://s.abcnews.com/images/Health/milk-stork-kate-torgersen-ht-mt-180805_hpMain_4x3t_240.jpg","credit":"Paige Courtney","ratio":"1x1"}}],"relatedContentSection":"news","schemaContent":{"name":"Mom's funny messages document her pregnancy","description":"Charlotte Chatman's Instagram posts are a viral hit.","duration":"0:52","uploadDate":"08-06-2018","publication":"08-06-2018","images":"https://s.abcnews.com/images/GMA/default-img-undefined.png","url":"https://service-pkgabcnews.akamaized.net/opp/hls/abcnews/2018/08/180806_gma_digital_BritneyMom1_,500,800,1200,1800,2500,3200,4500,.mp4.csmil/playlist.m3u8","contentUrl":"https://service-pkgabcnews.akamaized.net/opp/hls/abcnews/2018/08/180806_gma_digital_BritneyMom1_,500,800,1200,1800,2500,3200,4500,.mp4.csmil/playlist.m3u8","link":"https://www.goodmorningamerica.com/family/story/mom-channels-britney-spears-document-4th-pregnancy-57058209"}},"playlist":[{"id":"132281378","contentType":"story","section":"news"},{"id":"132283010","contentType":"story","section":"news"},{"id":"132273278","contentType":"story","section":"news"},{"id":"132231169","contentType":"story","section":"news"},{"id":"132206748","contentType":"story","section":"news"},{"id":"132200241","contentType":"story","section":"news"},{"id":"132054443","contentType":"story","section":"news"},{"id":"132054798","contentType":"story","section":"news"},{"id":"132033010","contentType":"story","section":"news"},{"id":"131912713","contentType":"story","section":"news"},{"id":"131830583","contentType":"story","section":"news"},{"id":"131834976","contentType":"story","section":"news"},{"id":"131554765","contentType":"story","section":"news"},{"id":"131554815","contentType":"story","section":"news"},{"id":"131543053","contentType":"story","section":"news"},{"id":"131432442","contentType":"story","section":"news"},{"id":"131121474","contentType":"story","section":"news"},{"id":"131247079","contentType":"story","section":"news"},{"id":"131228784","contentType":"story","section":"news"},{"id":"131178806","contentType":"story","section":"news"}],"kvps":{"pgtyp":"article","lang":"en","sp":"goodmorningamerica","programmatic":"true","bundleId":"com.abcnews"}},"analytics":{"accountID":"wdgnewwdgnewgmaweb","ns":"gma","pageName":"gma:family:video","pageType":"video","globalSpecVersion":"v1.08","siteDifferentiator":"gma:site","tagID":"g_page01","userABCookie":"0","section":"family","title":"Mom's funny messages document her pregnancy","pubTime":"14:24","pubDate":"08-06-2018","modTime":"16:01","modDate":"08-06-2018","taxonomyTags":"none","id":57058209,"editorialOtherSubjects":"","wordCount":"none","columns":"none","authors":"","authorsUnit":"none","authorsBureau":"none","subBrand":"Good Morning America","provider":"Good Morning America","videoName":"Mom's funny messages document her pregnancy","mediaAssetTitle":"GMA_Mom documents pregnancy with humor_180806","videoId":57058209,"mediaOnPage":"video","legacySlug":"/family/story/mom-channels-britney-spears-document-4th-pregnancy-57058209"},"taboola":{}},"request":{"headers":{},"httpVersion":"1.1","method":"GET","url":"/video/57058209","vary":{"host":"www.goodmorningamerica.com","cached":true,"path":"/video/57058209","forwarded-proto":"https","device":"desktop","userab":"0"}},"viewport":{"width":1260,"height":0},"user":{}};