Three weeks down and five to go in our annual fund-raising campaign on behalf of Children's Hospital, and we continue to exceed our record pace of 1984-85. We're about 20 percent ahead of the dollar count at the same time a year ago. Of course, it would be wonderful if that trend continues.

If past is prologue, it should. The next two weeks are the ones that always count heavily in our drive -- for very different reasons.

This coming week, people look up at the calendar and say, "Oh my gosh, I'd better give to the Children's campaign before Christmas."

The week after, they look up at the calendar and say, "Oh my gosh, I'd better give to Children's before New Year's Eve."

The first oh-my-gosh is all charity. The second is all accountancy.

Christmas Eve is a lovely and sentimental deadline by which to make a contribution. New Year's Eve is for the Form 1040-watchers. Dec. 31 is, after all, the last day you can write a check to the campaign and deduct it on your 1985 income tax return.

Whichever kind of donor you are -- bottom of heart or bottom of line -- the kids are counting on you, and so am I. Won't you do your part to help swell a fund that this community has been swelling for 40 years? I sincerely hope so.

Here are the Week Three totals:

Grand Total to Date: $91,516.16.

Total Given This Week: $39,662.23.

Individual Donors to Date: 1,340.

Group Donors to Date: 221.

If you'd like to help bump those numbers up, here's the way: TO CONTRIBUTE TO THE CAMPAIGN:

Make a check or money order payable to Children's Hospital and mail it to Bob Levey, The Washington Post, Washington, D.C., 20071.

Group donations haven't been waiting for either Christmas or New Year's. Some recent givers:

The Oldest Traveling Duplicate Bridge Club in the Army ($120, with a doubled and vulnerable thank-you to Rob Rufsvold).

The employes of Arrow General Inc. who work at the National Institutes of Health-Westwood Building ($46).

The Mount Vernon Area Stroke Club, a support group for stroke victims ($45 and thanks to physical therapist Kim Pickus).

Members of the Greater Washington Rug Craft Guild ($50).

The St. Vincent De Paul Society of Chillum ($75).

The Fairfax Hospital Tuesday Bridge Group ($30).

Greenbelt Post No. 136 of The American Legion ($500 "in memory of our departed comrades").

The Small Purchase Coffee Club at the Government Printing Office ($200).

The students at Beacon Heights Elementary School in Riverdale ($54.92).

Courtney Gallery of Northwest ($25).

The Division of Cosmetics Technology at the Food and Drug Administration ($105 -- the seventh year in a row this group has contributed).

The Running Brook Second Wednesday Bridge Group ($80, in memory of Earlene Dunn and in honor of Allison Norman).

JKD and Associates of Northeast ($20).

The students of Gaithersburg Junior High ($72.50).

And The Young-In-Heart Group at Congress Heights United Methodist Church ($15).

Terrific! Thanks to every one of you.