Home		Please select the first day of your last menstrual period: Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 Please select the number of days in your menstrual cycle: 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 You are most likely to become pregnant if sexual activity occurs during, just before, or just after ovulation. Ovulation occurs about day 14 of the menstrual cycle. The fertile days before and after ovulation vary among women. To calculate the days when you are most likely to become pregnant, enter the first day of your last period into the calculator.To determine the number of days in your cycle, count the days beginning with the first day of your last menstrual period (first day of bleeding) up to and including the day before your next period. This calculation is only possible if your menstrual cycles are regular, and is most reliable when the time between each menstrual period is in the range of 26 to 30 days. EBSCO Publishing's proprietary interactive calculators provide general results based on input provided by the user that is calculated against measurements or formulas considered standard by various government agencies, including the USDA, CDC, and FDA. The inputted information consists only of single values (e.g., anthropometric data or activity levels) not detailed clinical information, and the results do not indicate or suggest a specific course of action unique to the user. All EBSCO Publishing health and medical information found on this site is accredited by URAC. URAC's Health Web Site Accreditation Program requires compliance with 53 rigorous standards of quality and accountability, verified by independent audits. Sources Ovulation calculator. National Women’s Health Information Center website. Available at: http://www.womenshealth.gov/