Martha Stewart tried to keep up appearances yesterday, even though she was clearly in shock and agony as the ImClone scandal closed in on her.

"She can't believe this is happening," a source close to the lifestyle guru said of The Post's report that the New York Stock Exchange is probing her move to dump stock in the troubled biotech firm last year. 

The diva of all things domestic was talking up a storm when we spotted her shortly before 9 a.m. yesterday, after the gates to her Turkey Hill estate in Westport, Conn., opened and she pulled out in a silver SUV. 

She sat in the front passenger seat, talking agitatedly into a cell phone as the SUV drove off. 

We don't know what she was saying — she hasn't offered fans a magazine feature on lip-reading yet. 

Stewart remained on the phone as her driver wended his way into town — heading toward her TV studio, eight miles away on Newtown Turnpike. 

Our spy lost the SUV in traffic, and when he arrived at Stewart's studio, two of her employees were outside waiting for her. 

Did she make an unexpected detour? 

Her monthly calendar — the one printed in the June issue of Martha Stewart Living — lists only two activities for the day. 

Yes, only two activities — for the woman who can re-seed a lawn, tat a bathing suit, sponge-paint a mud room, clip her pet chinchillas' toenails and whip up a lemon caramel soufflé. All before lunch. 

The two items on her calendar? "Schedule tennis lessons" and "organize and inventory wine collection." 

It's unlikely she was heading for a tennis lesson. When we spotted her, she was wearing neither sporty whites nor a sporty demeanor. 

Perhaps she was heading for a local wine shop to replenish the Veuve Clicquot and the Brunello di Montalcino. 

It's also possible she went shopping — perhaps for antique hubcaps she'll fashion into teacups as a wedding gift. There's a wedding on her calendar for tomorrow, and a source told The Post she'll be attending. 

She did eventually show up at her studio. 

And stayed there with two guards posted outside, something locals have seen only once before - when Bill Clinton dropped by for a visit. 

What took place inside her studio will no doubt be shown on her TV show sometime soon. 

A source close to the company and familiar with Stewart's schedule said it was "business as usual." 

"Her calendar has not changed," said the source. 

Of Stewart's ImClone stock, the source said, "She gave her stockbroker an order to sell before it hit a certain amount." 

The source added, "She's upset. She's more concerned about her own [company's] stock price right now." 

As for her calendar — which lists her niece's graduation today, and a wedding and birthday party tomorrow — "She's keeping up her social appearances; nothing has changed," the source said. 

"She's going to be out east [to Long Island] this weekend," where she'll attend a benefit for the Group for the South Fork, a environmental advocacy and educational organization. 

Stewart is a "conservator" of the organization, which means she donated at least $2,500.

For more news, entertainment and sports coverage, click here for NYPost.com.