Among classes whose focus is on fertility awareness, also known as natural family planning:

AWARE. Method: Symptothermal, mainly. Non-sectarian feminist orientation. Classes begin this month. Phone 671-1063 or write Box 1361, Falls Church, Va. 22041.

CENTER FOR LIFE at Providence Hospital. Method: All natural methods including Sympto-thermal and Billings. Phone 269-7437. Charge on a sliding scale. Accepts singles, but prefers partner also attend.

COUPLE TO COUPLE LEAGUE. Method: Sympto-thermal. Classes one night a month for four months. Prefers couples, but will accept singles. Interfaith, with some religious orientation. Requests a $15 contribution for materials and manual. Phone: 671-5611.

HOWARD UNIVERSITY HOSPITAL CENTER FOR FAMILY PLANNING. Teaches all methods, including natural methods. No religious orientation. Charge: $5 or $10, depending on income. Phone 387-3743.

NATIONAL FAMILY PLANNING CENTER OF WASHINGTON, D.C. (Dr. Hanna Klaus' program). Method: Billings.Request $10 contribution. Group meeting and subsequent individual conferences. Singles or couples. Interfaith, with Catholic philosophy. Phone: 530-9383.

NATIONAL FAMILY PLANNING CLINIC. 384-5804. Method: Sympto-thermal. Sponsored by Archdioces of Washington, but open to all. Call 384-5804 between 6 and 10 p.m. for information or appointment. No charge. Iindividual counseling. Prefers couples.

WASHINGTON WOMEN'S SELF HELP. Method: Sympto-thermal. Classes the first Wednesday of each month and once a week for that month. Non-sectarian feminist orientation. Requests $10 contribution. Phone: 462-3224.