Two positive pregnancy test followed by two negative

BrokenJetpack

So I have a male friend that's been seeing a girl casually for the past while. They were last together about 14 / 15 July, and on Aug 11th that she told him she was pregnant. The thing is that she's had two positive results from home pregnancy tests, but more recently a negative pharmacy test from a visit to her doctor followed by a negative result from a blood test done by the doctor.

Here's the timeline:

• slept together about 14 / 15 July
• positive home pregnancy test on Aug 7th followed by another positive one on Aug 14th
• visit to the doctor on Aug 16th, negative urine test, negative result from blood test on Aug 18th

Her period is due in the next few days so they're waiting to see if it happens, and are also planning to get an ultrasound. But is there any reason why there would be two positive results followed by two negative ones?

Neyite

Different tests. The ones you get in the pharmacy - Clearblue and First response are usually pretty sensitive, doctors ones are dip-stick ones and multipack ones so can be less sensitive. If there was a negative blood test though, that's the most accurate marker as to whether or not pregnancy is now present. If it's negative on the bloods, then she's unlikely to be pregnant now even if she briefly conceived.

From the sounds of things she may have had what's called a chemical pregnancy where the initial fertilisation process began but it failed to implant.

Doesn't sound like they were planning a pregnancy, so fertility drugs aren't' a factor. (There's some ovulation stimulator drugs that can mimic the pregnancy hormone on a test so they warn you not to test until you are due to test for fear you get your hopes up and it's just the drugs.)

anndub

Yes. It's called a chemical pregnancy and is basically a very early miscarriage. Very common occurrence and of the reasons it's advised not to take a test before you've missed your period.

BrokenJetpack

https://www.boards.ie/discussion/comment/119495848#Comment_119495848

Oh.. ok. Hadn't heard of that. So this could happen by week 4? The negative blood test was about 4 weeks after they were last together. How accurate is a blood test at the 4 week stage?

BrokenJetpack

https://www.boards.ie/discussion/comment/119494303#Comment_119494303

Thanks wasn't aware of chemical pregnancy. Is it something that might need medical attention?

Big Bag of Chips

No. A chemical pregnancy is a miscarriage shortly after fertilisation and implantation of the egg. It usually occurs around 5 weeks of pregnancy (about 3 weeks after conception)

When an egg is fertilised next step is to implant in the lining of the womb and HCG, the hormone in your blood that rises when pregnant, is detected. This hormone drops or is not detected when miscarrying or not pregnant. HCG can be detected by a pregnancy test at 4 weeks, sometimes earlier (2 weeks post conception) giving a positive result, but then if the egg fails to implant in the womb properly the woman bleeds/miscarries and her HCG levels drop. Giving a negative pregnancy test result.

Often if the woman hasn't taken a pregnancy test, and has a bleed she just assumes this is a normal period and she was never pregnant. This period can sometimes be a little late. It's only if you take a test and realise that your HCG levels are raised that you know you are/were in the early stages of pregnancy.

anndub

Implantation would occur about two weeks after ovulation/conception. It would take a few of days after implantation for HCG to be detectable in a pregnancy test. That would typically be around the time of a missed period for anyone with a 28 day or less cycle. It sounds like she has a very long cycle so the two weeks was still a week before her period was due. An embryo made an attempt to get going but wasn't viable. It created enough HCG to get that positive pregnancy test but was not viable enough to sustain itself and HCG started to drop off again before the doctors visit. No medical attention would be needed for a chemical pregnancy but her period should really gave arrived soon after the negative tests.

xeniane

Home tests, especially early ones, are not accurate. I use one of the best apps, but even iyoni declares 94% of accuracy. The most reliable one is a blood test, and if it shows no pregnancy that means a woman is not pregnant.