Can a negative pregnancy test be inaccurate?
A repeated negative pregnancy test even with a missed period typically means that you are not pregnant. A negative pregnancy test a week or more after your missed period indicates that your chance of being pregnant is less than 1-2%. A positive pregnancy test usually means that you are pregnant. However, sometimes it is possible to be pregnant even though you had a negative pregnancy test.
What causes a negative test?
There are several reasons why you can have a negative pregnancy test. Maybe you miscalculated when your period was due. It's also possible you tested too soon and there is not enough hCG (the hormone that indicates pregnancy) found when you tested. You may need to wait another week and then retest.
When is the best time to do a pregnancy test?
hCG doubles about every 48 hours in early pregnancy, so a home pregnancy test that is negative on Monday could very likely be positive on Wednesday. However, if it's positive with first-morning urine, later on in the day, when the urine is more diluted, it could test negative. It is also important to remember that despite the advances in urine home pregnancy tests, blood tests are still the best at detecting early pregnancy.
The timing of a positive pregnancy test depends on implantation. If you are pregnant, a urine pregnancy test is not expected to be positive until 3-4 days after implantation (at the very earliest), which is about 10 days after ovulation/fertilization, and 4 days before the next period. About 51% of pregnant women have a positive pregnancy test two days before their next expected period.
Chances of being pregnant despite having a negative pregnancy test
|Chance of Still Being Pregnant With A Negative Pregnancy Test||Chance Of NOT Being Pregnant With A Negative Pregnancy Test||% Of Pregnant Women With A Positive Pregnancy Test|
|12 DPO||EP -3||12.3%||87.8%||51%|
|13 DPO||EP -2||9.5%||90.5%||62%|
|14 DPO||EP -1||8.0%||92.0%||68%|
|15 DPO||Expected period||6.5%||93.5%||74%|
|16 DPO||EP +1||5.3%||94.8%||79%|
|17 DPO||EP +2||3.8%||96.3%||85%|
|18 DPO||EP +3||2.5%||97.5%||90%|
|23 DPO||EP +7||1%||99.0%||96%|
In each menstrual cycle, there is an about 25% chance of getting pregnant. Your chance of getting pregnant each month may be different depending on your age, certain medical issues, whether you ovulate or not, and if you are trying to get pregnant with IVF or other fertility medications.
If you know you ovulated and your period hasn't come 15+ days post ovulation, then there could be only one likely reason: you are pregnant!