1 How long does it take to ovulate after the first positive result on the OPK (Ovulation Predictor Kit)?

You will most likely ovulate 12-48 hours after the first positive result on your OPK, and usually within 24-36 hours. Also, you do not need to keep testing for your LH surge once you get the first positive result. It is the first positive result that you are after.

2.2 How long after HCG does ovulation occur and how do we know?

Ovulation occurs 36-40 hours after the HCG injection. We know this from IVF observation. Eggs will release in this timeframe if they have not been retrieved.

2.3 How long do sperm live after timed intercourse or after IUI?

Normal, healthy sperm live approximately 48-72 hours. (Abnormal sperm may have a shorter life, which may vary according to sperm health.) We do know that washed sperm can survive in the IVF incubator for up to 72 hours. That would be considered the upper practical limit.

2.4 How long are eggs able to be fertilized?

Eggs are able to be fertilized for about 12-24 hours after ovulation. The older the woman, the shorter this time becomes.

2.5 How long does it take for fertilization to occur?

Fertilization occurs within 24 hours after ovulation.

2.6 How long does it take for implantation to occur?

Implantation occurs about 5-10 days after ovulation.

2.7 How soon can I take my Pregnancy Test (Beta HCG or Home Pregnancy Test)?

The earliest that a sensitive blood test can pick up any HCG at all is 5-7 days after ovulation. Your quantitative serum beta test can be reliable about 10-12 days after ovulation, if you have not taken a HCG booster. Extremely sensitive home pregnancy tests might in some cases be reliable as soon as 12 dpo. If you have taken a HCG booster, then you may have a reliable test at 14 days past ovulation. The serum beta is the most reliable test. Any level over a 5 is generally considered a positive result, although having a second blood test two days later should show the numbers nearly doubling. The "average" level of hCG is about 25 at 10 dpo, 50 at 12 dpo, and 100 at 14 dpo. Note that there is a difference between a qualitative and a quantitative test. A qualitative test gives a yes or no answer. Your HCG level has to be above 50 units to get a positive result. Quantitative tests give a value to the amount of pregnancy hormone in your blood. It gives a specific number. Anything greater than 5 is considered positive. Considering that it is possible to implant as late as 10 dpo, a qualitative beta might produce a false negative if used for an early pregnancy test.

2.8 How do you determine the first day of your cycle?

CD1 is the first day you see a red flow, not just intermittent spotting. There is no universal rule for the cutoff time for that date. Some RE's use midnight, others use 5 p.m., but most often CD1 is considered the first day of full flow that begins before mid-afternoon. Again, spotting does not count unless it is a continuous (not intermittent) spotting. Continuous spotting does count as CD1. The fact that the rules of thumb for calculating CD1 are so arbitrary suggests that you've got a little bit of leeway for variation.