Pregnancy Dates: When Did Conception Occur?

Pregnancy date

Your girlfriend had her period from July 12 to July 17.
They had intercourse on July 23 without ejaculation.
She had her period again from July 26 to July 30, and then had intercourse again from August 2 to August 5, during which there was ejaculation.
A pregnancy test in early September indicated she was five weeks pregnant.
You want to know when she likely conceived.

Based on this timeline, it is likely that she conceived during the intercourse that occurred between August 2 and August 5, as sperm can survive in the female reproductive tract for several days, and her ovulation may have occurred shortly after her period ended.

Wei, 20~29 year old female. Ask Date: 2022/09/24

Dr. Cao Guotao reply Obstetrics and Gynecology

Hello, it might be around mid-August.
Wishing you good health.

Reply Date: 2022/09/24

More Info

To determine the likely date of conception for your girlfriend, we need to consider her menstrual cycle and the timing of sexual intercourse. Based on the information provided, her last menstrual period (LMP) was from July 12 to July 17. Assuming a typical menstrual cycle length of 28 days, ovulation would likely occur around day 14 of her cycle, which would be approximately July 26.
Given that she had sexual intercourse on July 23, which is just a few days before her estimated ovulation, this could potentially be a time when sperm could fertilize an egg. However, you mentioned that there was no ejaculation during this encounter, which significantly reduces the likelihood of conception occurring from this event.

Following her menstrual cycle, she experienced another period from August 2 to August 5. If we assume her cycle is regular, ovulation would again occur around 14 days after the start of her next period, which would be around August 19. If she had sexual intercourse during this time, particularly if it involved ejaculation, this would be a more likely time for conception.

You mentioned that she tested positive for pregnancy in early September, indicating she was about five weeks pregnant at that time. This aligns with the conception window of late August, particularly around the time of ovulation.
In summary, while the sexual encounter on July 23 was close to her ovulation date, the lack of ejaculation makes it unlikely that conception occurred then. The more probable date of conception would be around August 19, following the sexual activity that involved ejaculation.
It's also important to note that pregnancy dating can sometimes be confusing due to variations in menstrual cycles and the timing of ovulation. Ultrasound measurements can provide additional insights, as they can help confirm gestational age and provide a more accurate estimate of when conception likely occurred.

If there are further uncertainties or concerns regarding the pregnancy, it may be beneficial for your girlfriend to consult with a healthcare provider for more personalized guidance and to discuss any necessary prenatal care.

Similar Q&A

When Did Conception Likely Occur? Understanding Fertility Timelines

On October 21 and 22, there was unprotected intercourse. An ultrasound on December 4 indicated a 7-week pregnancy, and another ultrasound on January 4 showed a 12-week pregnancy. I would like to know the likelihood of conception on those dates.

Dr. Huang Zifei reply Obstetrics and Gynecology
Dear Yung, From a theoretical standpoint, it is not possible to determine the exact date of conception between October 21 and October 22, as either date could be the date of conception. Sincerely, Dr. Huang Zifei, Department of Obstetrics and Gynecology, Nantou Hospital

Understanding Conception Timing: When Did Pregnancy Occur?

On February 16, there was intercourse with withdrawal method, and menstruation started on February 17. On March 21, there was intercourse with ejaculation inside, and there were also unprotected sexual activities during this period. An ultrasound on March 6 showed a gestational s...

Dr. Cao Guotao reply Obstetrics and Gynecology
Hello, it is difficult to accurately estimate the conception period; it is more likely to occur before menstruation. Wishing you good health.

Understanding Conception Dates: What You Need to Know During Pregnancy

Hello doctor, I am currently pregnant. My last menstrual period was on December 21, and my cycles are irregular, usually around 26, 27, or 28 days. The maternity handbook states that conception likely occurred on January 3. I would like to ask if the conception date refers to the...

Dr. Lin Wenbin reply Obstetrics and Gynecology
The correct date of conception can only be determined after an outpatient ultrasound examination.

Understanding Conception Dates: Key Factors in Fertility

The first day of the last menstrual period was January 27. Ovulation occurred, and unprotected intercourse took place. On February 28, protected intercourse occurred. What would be the estimated conception date?

Dr. Cao Guotao reply Obstetrics and Gynecology
Hello, that is likely to be the ovulation day. Wishing you good health.