Can You Have a LH Surge and Ovulate on the Same Day?

You cannot have an luteinizing hormone surge and ovulate on the same day. According to WebMD, LH increases rapidly shortly before ovulation. Ovulation occurs around 36 hours after the LH surge.

LH is a hormone that plays a role in regulating the menstrual cycle and egg production. It rises and falls at different times during the cycle, and a surge occurs just before ovulation, according to WebMD. Around halfway during a woman's cycle, LH levels rise alongside the follicle-stimulating hormone and encourage the ovaries to release an egg. In a 28-day cycle, this occurs around day 14. However, cycles and hormones vary between women, and they can change from month-to-month. The LH surge may therefore occur at a different time.

Women who are trying to conceive may use an ovulation-predicting kit to detect their LH levels. Like a pregnancy test that detects HCG, an ovulation-predicting kit shows two lines when LH surges above a particular level, which indicates that the woman may ovulate soon. According to Parents Magazine, ovulation-predicting kits from major market brands are around 97 percent accurate for detecting LH levels. Women who want to become pregnant then try to conceive in the 24 to 48 hours after a positive ovulation-predicting kit test. It is important to note that these kits only predict ovulation, and they do not indicate when it happens nor even guarantee that it is going to happen.