OPK instructions

First, you must determine the length of your menstrual cycle. This is the number of days from the first day of your menstrual bleeding to the day before your next bleeding begins again. Please refer to the chart below to determine when you should start testing. If your cycle is shorter than 21 days or longer than 38 days, consult your doctor. If you do not know your cycle length, you may begin the test 11 days after your first period since the average cycle length is 28 days. Perform 1 test each day over a 5 day period or until the LH surge has been detected.

Cycle Length

First test day

21 days Day 6
22 days Day 6
23 days Day 7
24 days Day 7
25 days Day 8
26 days Day 9
27 days Day 10
28 days Day 11
29 days Day 12
30 days Day 13
31 days Day 14
32 days Day 15
33 days Day 16
34 days Day 17
35 days Day 18
36 days Day 19
37 days Day 20
38 days Day 21

Urine collection

Do not use first morning urine samples as LH is synthesized in your body early in the morning. It will not show up in your urine until later in the day.

The best time to collect your urine is between 10am - 8pm (2pm is ideal).

Collect urine at about the same time each day.
Reduce liquid intake about 2 hours before collecting your urine as a diluted urine sample can prevent the test from detecting LH surge.


  1. Bring the test pouch to room temperature (18-30°C). Collect urine into a clean container (such as plastic cup). The best way to collect sample is by placing a cup in the middle of urination process. To begin testing, open the sealed pouch by tearing along the notch. Remove the test from the pouch when you are ready to use it.
  2. Immerse the strip into the urine with the arrow end pointing towards the urine. Do not immerse past the MAX (maximum) line. Take the strip out after 5 seconds and lay the strip flat on a clean, dry, non-absorbent surface (e.g., mouth of the urine container). Do not immerse for longer than 7 seconds.
  3. Wait for colored bands to appear. Depending on the concentration of LH in the test specimen, positive results may be observed in as short as 40 seconds. However, to confirm negative results, the complete reaction time (10 minutes) is required. Do not read the results after 30 minutes as this type of test is designed for rapid determination only.

Interpreting the results

No LH Surge:OPK test results

Only one color band appears on the control region or the test band is present but lighter in color intensity than the control band. There is no LH surge even if two lines present - as long as test line is fainter than the control line the result is negative.

LH Surge:

If two color bands are visible and the test band is equal to or darker than the control band, you will probably ovulate in the next 24-48 hours.

If you want to get pregnant, the best time to have intercourse is after 24 hours but before 48 hours.

 Good luck!