How to determine the father of the baby conceived?

Question

Hello doctor,

I got my normal cycle about eight months and two weeks ago. I got my second cycle eight months ago. I did not get a period seven months ago, so I took a pregnancy test at that time, and it was positive. However, I had two partners, and I am not sure who I conceived with because of the irregular cycles.

Kindly help.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

I read your query and understood your concern.

Thank you for being open. That is a completely valid concern, especially with irregular cycles and two possible partners. Let us walk through this carefully to help you understand when you likely conceived and what options you have to narrow it down.

Cycle overview:

About eight months and two weeks ago, you had a normal period.
About eight months ago, you had another cycle (15 days later). This may not have been a full period; it could have been implantation bleeding, hormonal spotting, or anovulatory bleeding.
About seven months ago, you had no period. Positive pregnancy test around the same time (seven months ago).

So, when did you likely conceive?

Let us estimate based on an average cycle and ovulation timing:

If your period from about eight and a half months ago was a true menstrual period, ovulation likely occurred about eight months ago.
If you had unprotected sex between about eight months and one week to eight months ago, that would probably have been your fertile window.
The bleeding that happened about eight months ago, shortly after your period, might have been mid-cycle spotting or even implantation bleeding, especially if it was lighter or shorter than usual. So, conception most likely occurred about eight months ago, give or take a few days.

Next steps:

Paternity test (most accurate): A non-invasive prenatal paternity test can be done as early as eight weeks into pregnancy using the mother’s blood and cheek swabs from both potential fathers. After birth, a standard DNA (deoxyribonucleic acid) test will provide 100 percent confirmation.
Dating ultrasound: If you have not already, an early pregnancy ultrasound (ideally done before 12 weeks) can estimate how far along you are with a few days of accuracy, helping to narrow down the conception date.

Please let me know if you would like help estimating based on ultrasound dates or if you want to build a timeline to track this more clearly.

I hope this helps.

Please let us know if you have any further queries. We would be happy to answer.

Thank you.