Determining the Likely Conception Date: A Guide for Expecting Mothers

Urgent! I would like to know which day I might have conceived?

On December 23, 2020, menstruation occurred.
On January 11, 2021, I had sexual intercourse with a friend.
For the rest of the time, I had sexual intercourse with my current boyfriend, starting from January 15, and we continued to have intercourse daily.
Due to irregular menstrual cycles, I did not pay special attention to it.
On April 1, I went for a prenatal check-up and discovered that I was already 10 weeks pregnant.
The obstetrician stated that my last menstrual period was on January 21, 2021, and my estimated due date is October 28, 2021.
Could you please tell me with whom I likely conceived and when?

Ms. Zhang, 20~29 year old female. Ask Date: 2021/10/22

Dr. Zhang Kunmin reply Obstetrics and Gynecology

Hello, based on your description, it is difficult to make an accurate assessment.
If necessary, I recommend undergoing DNA testing.
Thank you! Wishing you peace and health.
Dr.
Zhang

Reply Date: 2021/10/22

More Info

Determining the likely conception date can be a complex process, especially when there are multiple sexual partners involved around the time of ovulation. Based on the information provided, we can analyze the timeline to estimate when conception likely occurred.

Your last menstrual period (LMP) was on December 23, 2020. Typically, ovulation occurs about 14 days after the first day of your last menstrual period in a regular cycle, which would place your ovulation around January 6, 2021. However, since you mentioned that your menstrual cycle is irregular, this could vary.

You had sexual intercourse with a friend on January 11, 2021, and then with your current boyfriend starting January 15, 2021, continuing daily thereafter. Given that sperm can live inside the female reproductive tract for up to five days, if you ovulated around January 6, having intercourse on January 11 could potentially lead to conception if ovulation occurred later than expected.

However, since you continued to have intercourse with your boyfriend every day after January 15, it is also possible that conception occurred from these encounters. The fact that you were already 10 weeks pregnant by April 1, 2021, aligns with a conception date around January 21, 2021, which is consistent with having regular intercourse with your boyfriend during that time.

To summarize, while it is challenging to pinpoint the exact date of conception, it is likely that conception occurred between January 11 and January 21, 2021. Given the timeline and the regular sexual activity with your boyfriend after January 15, it is more probable that he is the father of the child.

In terms of medical advice, if you have concerns about your pregnancy or any related issues, it is always best to consult with your healthcare provider. They can provide personalized guidance based on your health history and current situation. Additionally, if you are experiencing emotional distress regarding the circumstances of your conception or relationships, seeking support from a mental health professional can be beneficial. They can help you navigate any feelings of anxiety or uncertainty you may have during this time.
It's important to remember that pregnancy can bring a mix of emotions, and it's okay to seek help and support from friends, family, or professionals as you prepare for this new chapter in your life.

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