An immediate dark positive result could mean that there's a high concentration of hCG in your urine, and the test is showing an immediate dark result due to the hormone level. One thing to note is that all home pregnancy tests are different and may detect hCG at different levels.
Elevated HCG Levels in Pregnancy Test
The darker the line on your pregnancy test, the more HCG is present in your body. If the line is very dark, it can be called a dye stealer, because there is so much HCG detected that it takes dye from the test line.
Confirming Your Pregnancy at 4 Weeks
A home pregnancy test can show a positive result at 4 weeks pregnant depending on your levels of the pregnancy hormone hCG (human chorionic gonadotropin), which is present in your urine when you're pregnant and increases as the pregnancy develops.
The darker line is usually the control line. Sometimes this second line is so faint, you can barely see it. If there is a line, not an evaporation line, but a true line, no matter how light, you should read that as a positive pregnancy test.
Home pregnancy test positive earlier than “normal”
If you get a positive test, especially a really dark positive, days before your period is even due, that may be one of the early signs of twins! The more babies you're carrying, the higher and faster your human chorionic gonadotropin hormone (hCG) rises.
Although the line should be darker in relation to higher concentrations of hCG, the actual amount of hCG in a sample of urine can vary. This fluctuation is due in large part to the concentration of your urine at any given time.
The longer you wait after implantation, the higher your hCG levels will be. The more pregnancy hormone present in your urine, the darker the line you will see on your pregnancy test.
In a healthy pregnancy, the levels of the hormone should double every 2 to 3 days. While the line might be faint at the very beginning of pregnancy, as time goes on and the pregnancy advances, the line that the test produces should get darker and more apparent.
High hCG levels could be a sign of gestational trophoblastic disease (GTD) or a molar pregnancy. If your early hCG reading is extremely high, you will need an immediate follow-up appointment to determine the cause.
If you see a positive line, you're pregnant
As your pregnancy progresses, levels of hCG will go up, making it easier for tests to detect.
After implantation, production of hCG starts from cells in the developing placenta (tissue that will feed the fetus). Trace levels of hCG can be detected as early as eight days after ovulation. That means you could get positive results several days before you expect your period to start.
Typically, you'll find out if you're having twins during a first trimester ultrasound. An ultrasound will usually be able to detect a twin pregnancy early on, but sometimes a twin pregnancy can be detected even earlier through a pregnancy blood test.
In a twin pregnancy, there are elevated levels of hCG, making it possible to have a very early positive result. However, home pregnancy tests won't confirm if twins are present, only the presence of hCG. It takes around 2 weeks after conception for hCG to be detected in a hCG pregnancy test.
Elevated Beta-hCG Levels
If you are using a regular pregnancy test (not the super-sensitive variety) and get an immediate positive (especially a very dark positive indicator) a few days before your period is due, there may be an increased chance that you are carrying twins.
Is the linea nigra a sign of any health condition? No, the linea nigra is not associated with any medical conditions during pregnancy. It's a completely normal part of being pregnant.
Therefore, when you have an ectopic pregnancy, you still have signs of pregnancy and the test still shows 2 lines. However, beta HCG levels will increase slowly, so the next test will be darker, and HCG will only decrease when it is a degenerative ectopic pregnancy.
“Higher hCG levels can be an indicator of a twin pregnancy, but it's not conclusive evidence,” Dr. Garg says. “Two placentas in twin pregnancies produce more hCG in comparison to the single placenta in a singleton pregnancy.” So, one explanation for a higher-than-average hCG level could be a normal twin pregnancy.
Be assured that it can take a variable amount of time (on average two weeks) for a woman's hCG level to disappear after a miscarriage.
Can a twin pregnancy be detected early on? Yes. A twin pregnancy can often be detected in your first trimester by an ultrasound Opens a new window at 6 weeks or later. If your healthcare provider checks your hcG levels, a higher-than-normal level can be a sign of a twin pregnancy.
At 4 weeks, the blastocyst is splitting into an embryo and placenta, and an ultrasound of your uterus will only show what looks like a tiny dot called the gestational sac, and will not show a pregnancy until it is further advanced.
Week 4 of pregnancy
For example, a fertilised egg may have implanted in your womb just 2 weeks ago, but if the first day of your last period was 4 weeks ago, this means you're officially four weeks pregnant! Pregnancy normally lasts from 37 weeks to 42 weeks from the first day of your last period.