AT SOME POINT in the women's movement, Mothers Who Stayed At Home rebelled at the implications of the term Working Mothers. The next thing we knew, we had the phrase Mothers Who Work Outside the Home. That's always been a little too unwieldly for me, so over the years. I've used a mental shorthand; there are working mothers and regular mothers.

As a working mother, I've always wondered what it's like to be a regular mother. Always is an exaggeration. It's the kind of thing I wonder about around holidays when there simply isn't enought time to do the extra load of shopping and entertaining that regular mothers do, or when the family undergoes a cataclysmic upheaval such as moving, or when a dread disease such as chicken pox strikes. When things get particularly frantic, you can always say, maybe I could handle it better if I weren't a working mother.

After the baby was born last August, there came a period of months in which I did not work outside the home. This was the perfect time to find out what it's really like to be a regular mother. And having been a working mother all these years, I had no end of things lined up for me to do around the house when I became a regular mother.

I knew from all the magazines I'd read just what a regular mother does: she swims or plays tennis an hour a day to keep a perfect figure in shape; she decorates her house with simple but exquisite taste saving the family scads of money by making the draperies and reupholstering the living-room furniture herself.

A regular mother spends a day each week cooking six gourmet meals ahead of time and freezing a second portion of each in case her husband should bring home important business associates unexpectedly. The regular mother is shiny and bright, her children are clean and well mannered, and when her husband arrives home from work in the evenings the regular mother presents him with a loving kiss and a martini that is, in Red Smith's ideal, bitter cold and powder dry.

The regular mother comes into her own at holiday time, making centerpieces for the dining table, strolling through the suburban malls in search of the perfect gift for her loved ones and getting packages mailed by Dec. 5. The regular mother has everything wrapped and hidden away by the 20th, so that she is able to throw an intimate Christmas soiree for the neighborhood and 75 of the couple's closest friends on Dec. 23.

The regular mother is up on the latest novel and the latest memoirs. She is able to articulate intelligent concerns about world affairs.

The regular mother is not me.

Yes, some redecorating got done while I was home being a regular mother, but my friend the decorator wisely counseled at the outset that it would be best if I spare my family and not try to do anything myself. No draperies, no painting, and above all no reupholstering, she said, pointing out as diplomatically as possible that I didn't know how to do any of these things and would no doubt ruin my house if I tried. So, in effect, I decorated like a working mother.

No gourmet cooking got done, not even the occasional canard a l'orange I made when I was a working mother. Now, I could serve guilt-free pizza, but I did spend a lot of time in the kitchen. Once I became a regular mother, it seemed my children ate snacks constantly and if I wasn't feeding them I was feeding the baby, or rinsing dishes and putting them in the dishwasher.

My children also seemed to have more errands than ever before -- bikes and lawnmowers that needed fixing, trips to the library, to friends, to doctors, to the store. The 4-year-old who used to go to a play group in the afternoons suddenly had an empty social schedule that needed filling. And both he and the 13-year-old had many conversations that they wanted to hold. We have discussed alcohol and drugs and the merits of sex education in the schools. We have discussed Superman and Spiderman and whether the cat likes the baby and whether the baby has bones.

The closest I got to swimming was taking the 4-year-old for lessons, and the closest to tennis was putting on tennis shoes. After a while, I noticed I was double-knotting them.

I did articulate intelligent concerns about world affairs. Some months ago, I discussed Iran with our Iranian pediatrician and was so taken with a perception he shared with us that I repeated it at home. A lot. "Mom," said my 13-year-old, finally throwing up his arms in exasperation, "that's the 12th time you've told us that story." Then I realized what could happen to regular mothers: They become quite taken with their pediatricians, not because they are brilliant physicians, but because they are the only other adults they talk to for months on end.

In five months, I have not finished a novel. Not writing one. Reading one. I have not finished "The Brethren." I have not seen "Kramer vs. Kramer." I have not even opened a seed catalogue. h

And the holidays were more frenetic than usual. I got all of the Christmas presents for my husband and children, not by strolling through suburban malls and shopping lovingly for the perfect present, but by swooping through four stores in three days like some woman in a movie reel stuck on fast wind. Thoughtful gifts to relatives were replaced by last-minute checks. We sent a total of 25 Christmas cards. I scrawled warm personal notes such as "Love to all" under the Season's Greetings.My husband addressed the envelopes. They were mailed the 23rd.

As for our Christmas soiree, well, we're going to have to postpone that at least until next year when I'm Working Outside the Home again. Maybe I can handle it all better when I'm not a regular mother.