Determining Conception Date: Who is the Father of My Baby?

Please help me check the date of conception..?

I have been trying to conceive for over a year, and finally, I became pregnant.
However, due to a mistake, I am facing a very troubling issue and I deeply regret it.
I am also feeling helpless and unable to express my feelings.
Please, doctor, help me determine my conception date; I need to confirm who the father of my child is.
My menstrual cycle lasts about 4 to 5 days, with a cycle length of approximately 30 days.
My last menstrual period started on February 19 and ended on February 22.
I had unprotected intercourse with a male friend on February 23 and February 27.
From February 28 to March 6, I had intercourse with my husband (as we are trying to conceive).
I used ovulation test strips from March 2 to March 5, and on March 5, the test showed two very dark lines.
Prior to that, the tests showed one dark line and one very faint line.
Since my periods are usually very regular, when my period did not arrive on March 21, I used a pregnancy test, which surprisingly showed two deep red lines.
On March 26, I went to the obstetrics and gynecology department for a vaginal ultrasound, which revealed a small dot.
The doctor said the gestational sac is forming and asked me to return in two weeks to hear the heartbeat.
I am very happy but also very scared.
The ultrasound image has some numbers that I do not understand, but perhaps they can serve as data.
The numbers on the top right corner of the photo are Tls0.32, MI 1.05, and on the left side GY, ER4-9, 8.0CM, 49Hz [2D] Pen, Gn48, DR 106, Map7, FA2, P90%.
This is the ultrasound content from March 26.
Could you please help me interpret this? Given the short time frame, would February 23 and 27 be considered safe days? Who is the father of this child? I apologize; it was not intentional, but I have my reasons.
Thank you very much for your help.

JJ, 30~39 year old female. Ask Date: 2018/04/02

Dr. Zhang Kunmin reply Obstetrics and Gynecology

Hello, the duration and frequency of intercourse described are too close together to make an accurate assessment.
If necessary, it is recommended to consider DNA testing.
Thank you! Wishing you peace and health, Dr.
Zhang.

Reply Date: 2018/04/02

More Info

Determining the paternity of a child can be a complex issue, especially when multiple sexual encounters occur within a close timeframe. Based on the information you've provided, let's break down the details to help clarify your situation.

Your last menstrual period (LMP) started on February 19, and you had unprotected intercourse with a male friend on February 23 and 27. You also had unprotected intercourse with your husband from March 1 to March 6, with ovulation tests indicating a peak on March 5. You received a positive pregnancy test on March 21, and an ultrasound on March 26 showed an early gestational sac.

To estimate the conception date, we typically use the LMP as a reference point. Given a regular menstrual cycle of about 30 days, ovulation likely occurred around March 5, which aligns with the peak results from your ovulation tests. Sperm can survive in the female reproductive tract for up to five days, meaning that intercourse on February 23 and 27 could potentially lead to conception if ovulation occurred shortly after those dates. However, since you had unprotected intercourse with your husband during your fertile window (March 1-6), it is also possible that conception could have occurred from those encounters.

The ultrasound performed on March 26 showing a developing gestational sac suggests that you are approximately 4-5 weeks pregnant at that time, which aligns with the ovulation date of March 5. This would indicate that conception likely occurred around that time, making it more probable that your husband is the father, given the timing of your sexual encounters.

However, it is important to note that without a DNA paternity test, it is impossible to definitively determine the biological father of the child. If you have concerns about paternity, a DNA test can provide a clear answer after the baby is born.
In summary, while the timing of your sexual encounters suggests that your husband is likely the father, the possibility of conception from the earlier encounters cannot be entirely ruled out. If you are feeling anxious or uncertain, consider discussing your feelings with a healthcare provider or a counselor who can provide support during this time. Remember, open communication with your partner is also crucial as you navigate this situation.

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