The first weeks signs of pregnancy are easily overlooked…

During the first weeks signs of pregnancy are easily overlooked. The first week of pregnancy is counted from the last day of your menstrual cycle previous to the conception. It is only in week two that ovolation and posterior fertilization occurs.  Therefore, you will not experience any symptoms during the first week. In fact, while you may experience some symptoms before, the majority of symptoms start on week six. This is when your body becomes fully adapted to pregnancy in a process controlled by hormones. Hormonal peaks are accountable for most of the symptoms experienced.

For the majority of women the most obvious sign of pregnancy is a missed period. However, many women do not have regular menstruation cycles and have to be alert to other symptoms in addition to lack of menstrual bleeding. The first signs of pregnancy usually appear in the first few weeks of pregnancy even before you miss your period. You have to take into account that not all women are equal and these symptoms may vary. You might have them all or you might have none.


The most common early symptoms of pregnancy include:

  • Usually termed morning sickness, it can appear at any time during the day or night. This symptom can start three weeks after conception.
  • This is caused by the increase in the levels of progesterone that leads to sleepiness.
  • Mood swings. Due to hormonal changes you might feel unusually emotional.
  • Breast tenderness. The hormonal alterations can result in increased breast volume and sensitivity.
  • Cramping
  • Food repulsions or cravings.The nausea is usually associated with increased susceptibility to smells which can lead to aversion to some foods. On the other hand, you can start craving certain food items you did not before.
  • Due to the blood vessels dilating during pregnancy you can feel dizzy when your blood pressure drops.
  • More frequent urination
  • Vaginal bleeding. It usually appears in the menstruation period but is much lighter than the usual bleeding. This is known as implantation bleeding since it occurs when the egg implants in the uterine wall (10 to 14 days after fertilization).
  • Your digestive system can slow down due to hormonal changes.
  • Change in vaginal discharge. Pregnancy can increase vaginal discharge and increases the incidence of thrush.
  • Darker vulva and vagina (Chadwick’s sign). While these tissues are usually pink they change to dark purplish-red with the progression of pregnancy due to increased blood flow.
  • Increase in body temperature. If your basal morning temperature remains elevated after day 16 of post-ovulation (Luteal phase) it is likely to be the first physiological sign of pregnancy. Of course this is only detectable if you are keeping track of temperature daily.

Keep in mind that you have to be cautious when considering these symptoms. Everyone is different and you must know yourself to identify if something unusual is happening. The early pregnancy symptoms are easily mistaken for regular menstruation associated issues (bleeding, cramping and mood swings for example). On the other hand they can also be associated to some diseases.  If you have any of these symptoms it is better to take a pregnancy test to be sure that you are pregnant.

Pregnancy tests

How do they work?

Most pregnancy tests are based in the detection of human chorionic gonadotropin (hCG) in urine or blood. This hormone cannot be detected before implantation of the embryo in the uterine wall, which occurs six to twelve days after fertilization.

There are other tests based on early pregnancy factor (EPF) presence in blood, which is detectable within 48 hours of fertilization. However, EPF testing is expensive.

Home pregnancy tests come in a variety of forms and are an easy and practical way to confirm if you are pregnant.
In order to be reliable you need to take some factors into account before performing a pregnancy test:

  • If you take a test too early there is a higher probability of a false negative (you might be pregnant but the test is not able to detect it yet).
  • Most home pregnancy tests can be done three to four days before your expected period.
  • It is best to do the test with the first urine of the day.
  • If the result is a faint positive or negative, but your period is still missing, you should repeat the test in a few days
  • The accuracy of the test itself is usually higher than 99%, however actual accuracy is around 75% due to misunderstanding of the instruction. This can lead to false negatives or false positives.
  • A false positive can occur if you are taking any of these medications: phenothiazines, chlorpromazine, and methadone among others.

Taking these limitations into account it is better to take a laboratory test to make sure that you are pregnant since it is more accurate. Other reliable method is obstrectic ultrasonography that can detect the gestational at four and a half weeks of gestation (or two and a half weeks after ovulation).


Symptoms in the later stages of pregnancy

With the progression of pregnancy your body will suffer more changes to accommodate the development of the embryo. This is a result of the hormone and chemical changes that place a great demand on your body.

  • Increased heart rate. Your heart will begin pumping faster since it has to supply blood to the fetus.
  • Weight gain. The hormonal changes can cause an increase in appetite.
  • Bigger breasts. The breasts and areola grow larger due to increased blood flow. Your nipples can also get darker and start leaking.
  • This symptom is more common in people who have experienced an acne bout before pregnancy.
  • Mucus plug. This is not usually noticeable, but you develop a plug to seal the opening in the cervical canal.

The good news is that many of the symptoms you experience in the first trimester begin to fade in the second trimester. Others however can stay the same or get worse. It is important that you speak to your physician so that he can recommend you treatments to alleviate these symptoms.