Questiontrying to get pregnant for first time. checking basal temp and had increase on day 13. dropped back down then on day20 had increase again.
AnswerDear Helen,
In order to effectively utilize basal body temperature (BBT) as an indication of ovulation, you really need to chart BBTs for at least 2-3 months to establish a pattern. MANY things can affect your BBT slightly for a brief period of time - contact with a virus that your body fights off, fever, a restless night's sleep, smoking a cigarette, or alcohol consumption the night before. Even coffee the night before, if it affects the quality of your sleep that night, may affect your BBT. This is why it is always very important to take the temps the first thing upon awakening so that you won't have many variables that can influence it. This means before doing ANYTHING at all.
A "normal" BBT chart is "biphasic", meaning there are two temperature phases. The early temperatures before ovulation are lower than temperatures during the next half of the cycle, following ovulation. The average BBT is 97.48F plus or minus 0.25 during the phase prior to ovulation (follicular phase) and 98.09F plus or minus 0.22 in the phase following ovulation (luteal phase). If conception occurs, the temperature stays at the elevated level and never goes down.
A shift in BBT, following ovulation, to the "hyperthermia phase" of the cycle should occur within a period of 48 hours or less. If you are charting your temperatures, you will typically see that three consecutive daily BBTs are at least 0.36 degrees F higher than the previous six daily temperatures.
This BBT rise precedes or coincides with ovulation and is associated with the increased production of progesterone by the ovary. Your BBT chart does not predict the day of ovulation, but rather provides evidence of ovulation 2-3 days after it has occurred. This can be helpful in predicting ovulation once several months have been charted and you are able to see a pattern.
In order to properly interpret your chart, you need to be able to draw a coverline. To draw the coverline, remember the general concept that you are always eyeing the last six temperatures at a time. The first day you see a temperature of at least .2 degrees higher, than the highest of the last six days, you assume you've had a thermal shift. Then count back six temperatures, highlight them and draw the coverline one-tenth of a degree above the highest of those temperatures.
Once your temperatures have been above the coverline for at least three days, you can safely assume that you have ovulated.
I hope this information has helped you and answered your question. I wish you the best of luck!
Brenda
