HealthCareMagic is now Ask A Doctor - 24x7 | https://www.askadoctor24x7.com

How Is Exact Day Of Fertilization Determined?

Posted on Mon, 12 May 2014

Question: Hi, I had my period March 10th, and had unprotected sex every weekend after, the last encounter being on March 31rst. He didn't orgasm and I took the morning after pill 8 hrs later just to be safe. On April 5th, 5 days after the encounter I took an at home pregnancy test an was positive. On Friday April 18th,I had an Ultrasound and they dated me 5 weeks 4 days. What are the chances that it was the March 31rst encounter tat impregnated me?!

Answered by Dr. Dr. Ivan Romich (36 minutes later)

Brief Answer: Hi an welcome to HCm Detailed Answer: The chances are negligible. In early pregnancy, ultrasound may miss several days or 1 week,rarely more than this. embrios after 2 weeks and 5 weeks are easily differentiated by ultrasound. so it almost impossible that ultrasonographer would misdiagnose 3 weeks. You can also measure your beta HCg levels and it will show is there any mistake about all this, but it is very likely that you became pregnant in the middle of march.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Dr. Ivan Romich (7 minutes later)

Sorry, I didn't understand anything you just said, so could you please explain again.

Answered by Dr. Dr. Ivan Romich (2 hours later)

Brief Answer: hi Detailed Answer: I am saying that sonography can verify the size and the development of embrio so almost the exact day of fertilization can be determined. Ultarsound have a margin of error of roughly 1 week. so it is hard that there is some mistake if doctor told you that it was 5 weeks,4 days. COnsidering this there is very, very low chance that march 31 was encounter that impregnated you. Your last period may have been implantational bleeding or there was fertilisation the next weekend.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Dr. Ivan Romich (34 minutes later)

So you believe by what I have said march 31rst couldn't be the time due to ultra sound results, and taking morning after pill, and having a positive pregnancy test just 5 days after that encounter!!

Answered by Dr. Dr. Ivan Romich (16 hours later)

Brief Answer: hi Detailed Answer: Yes, if everything you said is true, then the possibility that it was 31st march is negligible.

Note: For further follow up on related General & Family Physician Click here.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar