Why would someone who is 4 weeks pregnant get a negative pregnancy test result?

Answer 1

For some women the HcG hormone level is very low in early pregnancy and it doesn't register on the test.

The only thing to do, if you still suspect pregnancy, is to wait a week or two and try again. Early morning is the best time to test.

Answer 2

The pregnancy hormone is not large enough yet. 4 weeks pregnant means they are probably right at the first day of their missed period. Sometimes it takes a few days after for the test to be positive.

Test in the morning. That is when HCG is highest.

Answer 3

Absolutely! It is not uncommon for a woman to get a negative test result, when she is indeed pregnant, even when testing after her period is due.

The biggest reason for getting a negative test result is miscalculating your period. The average menstrual cycle is 28 days. If you are fortunate enough to have a regular 28 day cycle, you would count 28 days from the start of your last menstrual cycle to determine when your next period is due. The problem with this method is two-fold. One, many women do not have a 28 day cycle and two, this does not account for variations in ovulation dates and more importantly the date of implantation.

Some basic physiology

Your menstrual cycle is divided into two phases. The first half is called the follicular phase and lasts from the start of menstruation until ovulation. The second half is called the luteal phase and starts at ovulation extending outward until pregnancy or until menstruation begins again. During the follicular phase of your cycle you will produce hormones, specifically LH (luteinizing hormone) and FSH (follicle stimulating hormone). After ovulation occurs it triggers a rise in a second set of hormones, progesterone and estrogen. The length of the follicular phase can vary greatly. The luteal phase, from ovulation onward, is typically 13 to 14 days. So let's say a woman's typical cycle is the standard 28 days, but for this cycle our hypothetical woman's follicular phase is 16 days instead of her typical 14 days. This would mean if she tested the day her period was "due", she would actually be testing at 12 days past ovulation verses what she is assuming to be 14 days. The two day difference could be the difference between a negative and a positive pregnancy test.
Implantation and pregnancy tests

Another factor to consider is when implantation occurs. You will not get a positive pregnancy test until after implantation occurs. Although hcg is produced almost from conception, it is not until the egg implants that the hcg can be released into the woman's blood stream in sufficient quantities to result in a positive pregnancy test. The time implantation occurs varies. Implantation can occur anywhere from 6-12 days past ovulation.
Other causes for a pregnancy test to not detect pregnancy

Other causes for a negative test include diluted urine, expired test, improper testing, and ectopic pregnancy. If you have received a negative test result a day or two after your period is due, it may be as simple as testing too early. Retest again in a week, and if still negative consult your doctor.

The at home pregnancy tests are designed to detect HCG, known as the pregnancy hormone. So, a pregnancy test will not be positive unless HCG is detected in the body. This could result either from pregnancy or from the woman taking some form of medicine with HCG in it. Most of the time a positive pregnancy tests means the woman is pregnant. But, what happens if the test is negative the next day? Are you still pregnant? Was the first test wrong? There could be any number of answers, but the most likely one is that you were pregnant when you took the first test that was positive. Or, you could have been pregnant a few days prior to taking the test but the level of HCG was still high in your body. By the time you took the second pregnancy test the HCG levels had fallen enough that the test was negative, meaning you had a miscarriage.

This seems devastating to many women who are desperately trying to become pregnant. The one positive test followed by a negative one seems too much to bear. However, this is actually very normal. It is estimated that as many as 25% of pregnancies result in miscarriage. However, the miscarriage occurs so early that the woman never realizes what happened. The woman's period may be a bit heavier or later that particular month, but most women never have a clue a miscarriage occurred and because of this never feel the loss.

The problem for women who are doing everything possible to become pregnant is that they have the resources to test at home with ultra sensitive pregnancy tests. This allows them to find out they are pregnant very quickly after conception occurs. However, the problem here is that many pregnancies don't survive very long, but they do exist long enough to increase a woman's HCG level and result in a positive pregnancy test. This allows women to know about every miscarriage and feel every loss, which is not something most women deal with.

The best advice for women who are trying to become pregnant is to simply wait until they miss their period to take a home pregnancy test. This may seem like too long to wait when there are really sensitive tests that may be taken sooner. However, waiting a little longer will give you more accurate results. If you take the test and it is negative you will know to try again and if it is positive more than likely it will stay that way. Of course, the entire first trimester may be iffy when it comes to whether the pregnancy will make it or not, but the less you stress about it the better off you will be!

Good Luck! :)

Answer 4

Depends - if your hcg levels were detected on a blood test...but maybe weren't high enough to reach the hpt's hormone threshold to test positive? You're short on details, so it's just a guess.

Answer 5

i tested neg till i was 4 months on both pregnancys .with both blood and urine

Answer 6

if you mean 4 weeks from LMP, there is not yet enough HCG for the test to measure.

Answer 7

it could be to early to test

Answer 8

thats something someone would have to ask their doctor..