Having a good understanding of your menstrual cycle can help you time intercourse and increase your chances of becoming pregnant.
Understanding Your Menstrual Cycle
On average, a woman’s menstrual cycle is 28 days long, but it can vary—from 17-36 days. Day 1 of your menstrual cycle begins on the first day of your period. Between Day 7 and 11, the lining of your uterus begins to thicken, preparing for a fertilized egg to implant. Around Day 14 of a 28-day cycle, changes in hormones cause a mature egg to be released from an ovary (called ovulation) and travel down a fallopian tube. It is here that a sperm may fertilize the egg. The fertilized egg will travel toward the uterus for implantation. If this happens and the egg attaches to the lining of the uterus, pregnancy occurs.
When trying to get pregnant, it is helpful to know when the egg is released. That is the best time to achieve a pregnancy. The table below describes 4 of the most common methods that can be used to track when you are most fertile each month.
- To find the first day when you are the most fertile, subtract 18 from your shortest cycle, and mark an X on your calendar on this day of each cycle. (For example, if your shortest cycle was 27 days, the first day you are the most fertile will be Day 9 of your cycle; 27-18=9.)
- To find the last day you are fertile, subtract 11 from your longest cycle and draw an X through this date. (For example, if your longest cycle was 29 days, the last day you are fertile will be Day 18 of your cycle; 29-11=18.)
- One type is used to measure LH for the days during your menstrual cycle you are most likely to be fertile (see the calendar method above). These kits are inexpensive.
- The other type of kit measures your LH level daily. It tells you when your fertility is low, high, and peak. These testing machines are more expensive and require the purchase of test strips as well.
- Reviewer: Andrea Chisholm, MD
- Review Date: 01/2017 -
- Update Date: 03/15/2015 -