It was concluded that presence ofcannabinoids in urine or blood is not unequivocal proof of active cannabissmoking. Giardino 25 26 found THC-acid levels of up to 30-50ng/ml from passive-exposed subjects, and recommended a threshold of 65ng/ml to differentiatebetween active and passive smoking of cannabis.ticht & Kaferstein 20 estimated that the blood THC concentrationsproduced in a 70kg person smoking 15mg THC would peak at 7-8 minutes,after 30 minutes between 14-42ng/ml, and at 60 minutes between 7.5-14ng/ml.3.3 McBay 21 compared THC and THC-COOH levels in a study involving smokedmarijuana cigarettes.
Calculation Using An ovulation Calendar: 1  The first day of a period is considered as day 1. 2  Usually on day 14, the egg is released and is waiting for the sperm to fertilize it. 3  The egg has a lifespan of just 12 to 24 hours whereas a sperm can last for about 72 hours in a woman.
Sperm can live for three to five days, but the egg is around for only 12 to 24 hours. To increase the likelihood of conception, it's important to have daily intercourse in the days leading to ovulation and on the day you ovulate.A good approach is to have sex one to two days before ovulation and again on the day you ovulate.That way, there's more likely to be a healthy supply of sperm waiting in the fallopian tube when an egg is released. Of course, exactly when a woman ovulates isn't altogether clear.ut if you have a 35-day cycle, you would ovulate around day 21, not day 17. (Day 1 is the first day of your period.). To determine the time when you're most likely to be fertile, try our ovulation calculator.