Hi, I have a dilemma because a female claims she ended her period on July 13, 2010 (not sure if that’s true or not). We met for the first time and had sex on July 14, 2010 and many days after. On July 27, 2010 she got a blood test at the doctors and it said she was pregnant and the hcg level was at 27. Im not sure what she told the doctors and if that played a part in the due date or if its based off of ultrasounds and hormone levels but the due date given was April 25, 2011 by her doctor. A due date of April 15, 2011 was given based on a couple unexpected trips to the hospital for spotting. They checked her hormone levels and did measurements of the sac by transvaginal ultrasound at the hospital on Aug. 24, 2010. At the hospital they couldn’t see the baby until the following week but tried measuring the sac and said she was approximately 5 weeks and 1 day based on what they could gather and see. She was having sex with multiple guys around the same time period for a while now. When would she have most likely gotten pregnant? Is finding out she’s pregnant within 13 days after having sex and having the hcg level at 27 likely? How soon can you find out you’re pregnant by blood tests after having sex? How far along could she have been at the point she found out she was pregnant? How accurate is the due date based on the size of the baby by the ultrasound? How much could false information she’s giving them affect the due date? Also is it possible they couldn’t see the baby if she was more than 5 weeks pregnant (perhaps 7 or 8 weeks)? She’s very dishonest and a habitual liar and I am very stressed and don’t want to wait months hoping it’s not mine but not knowing. Based on all the facts given and the due date given by her doctor based on the ultrasound pics, what conclusion or opinion do you have on what’s going on and what I should think?
A blood HCG level is a good way to calculate gestational age. A general rule of thumb is that HCG should double every 48-72 hours in early pregnancy. An HCG level greater than 25 mIU/mL is considered enough evidence for pregnancy.
To answer your question, a blood test for HCG detecting a level of 27 mIU/mL is perfectly reasonable 13 days after ovulation. A pregnancy can be detected with an HCG level of 25-50 within 10 days of conception. In other words, factoring in transit time for sperm and egg migration, you could potentially be the father. It is important to note that HCG values are not as accurate as ultrasound at 5-6 weeks of gestation in estimating fetal age and delivery date.
Given the facts that you have presented, it is perfectly reasonable to assume that you are the father of the child. However, if she had sexual relations with more than one partner during the time in question, then someone else could be the father. Either way, a paternity test would offer the most definitive answer.
