Prince Harry and Meghan Markle
Meghan Markle and Prince Harry are showing signs of pre-wedding jitters. Pictured: Prince Harry and Markle attend the Women's Empowerment reception hosted by Foreign Secretary Boris Johnson during the Commonwealth Heads of Government Meeting at the Royal Aeronautical Society on April 19, 2018 in London. Getty Images/Chris Jackson

Meghan Markle and Prince Harry's royal wedding is only a few weeks away, and according to a body language expert, the couple is already showing signs of pre-wedding jitters.

This week, the bride- and groom-to-be have made several appearances in the Commonwealth Heads of Government meeting. In one event, the "Suits" star wore business-like attire with a jacket thrown over her shoulders. According to Judi James, based on the couple's attire and body languages, they are suffering the pre-wedding jitters.

"With the wedding only four weeks away Meghan and Harry have entered the most stressful time of any engagement," the expert told Daily Star. "There are hints in their body language that they could be suffering from the infamous pre-wedding jitters that nearly all couples fall prey to, no matter how much they're looking forward to the big day."

Among the subtle signs that James noticed is Markle using her jacket as a cloak. According to the expert, it suggests "feelings of vulnerability and a desire to be cuddled or reassured."

James also noticed Prince Harry doing a small trouser-hike. "When men are under pressure they often suffer an increase of 'checking' rituals that involve clothing. Prince Charles pats his pockets and fiddles with his cuffs and his son seems to be using clothing-touches as a similar self-calming trait," she said.

Meanwhile, she also noticed that there's a decrease in Prince Harry and Markle's touching. According to her, another sign of wedding jitters is one a couple who couldn't keep their hands off each other become less tactile.

In addition, James has observed that Markle keeps her distance from her future husband. In fact, the actress was photographed walking ahead Prince Harry at times, which she believes was done on purpose by the actress.

"Meghan walks with a slightly larger gap between herself and Harry here and by bringing up her inside arm in a hair preen gesture she gets to show off her ring but also create a subtle barrier that emphasises her independence as a royal-to-be," James explained.

Prince Harry and Markle are tying the knot on May 19 at St. George's Chapel at Windsor Castle. The wedding ceremony will begin 12 p.m. UK time (7 a.m. EST).