The clear blue tests are pretty accurate - which is why they are probably the most bought pg test.
Re-test using a different make - one that shows the lines rather than the wording.
Implantation Bleeding:
Implantation bleeding can be one of the earliest pregnancy symptoms. About 6-12 days after conception, the embryo implants itself into the uterine wall. Some women will experience spotting as well as some cramping.
Other Explanations: Actual menstruation, altered menstruation, changes in birth control pill, infection, or abrasion from intercourse.
Delay/Difference in Menstruation:
A delayed or missed menstruation is the most common pregnancy symptom leading a woman to test for pregnancy. When you become pregnant, your next period should be missed. Many women can bleed while they are pregnant, but typically the bleeding will be shorter or lighter than a normal period.
Other Explanations: Excessive weight gain/loss, fatigue, hormonal problems, tension, stress, ceasing to take the birth control pill, or breast-feeding.
Swollen/Tender Breasts:
Swollen or tender breasts is a pregnancy symptom which may begin as early as 1-2 weeks after conception. Women may notice changes in their breasts; they may be tender to the touch, sore, or swollen.
Other Explanations: Hormonal imbalance, birth control pills, impending menstruation (PMS) can also cause your breasts to be swollen or tender.
Fatigue/Tiredness:
Feeling fatigued or more tired is a pregnancy symptom which can also start as early as the first week after conception.
Other Explanations: Stress, exhaustion, depression, common cold or flu, or other illnesses can also leave you feeling tired or fatigued.
Nausea/Morning Sickness:
This well-known pregnancy symptom will often show up between 2-8 weeks after conception. Some women are fortunate to not deal with morning sickness at all, while others will feel nauseous throughout most of their pregnancy.
Other Explanations: Food poisoning, stress, or other stomach disorders can also cause you to feel queasy.
Backaches:
Lower backaches may be a symptom that occurs early in pregnancy; however, it is common to experience a dull backache throughout an entire pregnancy.
Other Explanations: Impending menstruation, stress, other back problems, and physical or mental strains.
Headaches:
The sudden rise of hormones in your body can cause you to have headaches early in pregnancy.
Other Explanations: Dehydration, caffeine withdrawal, impending menstruation, eye strain, or other ailments can be the source of frequent or chronic headaches.
Frequent Urination:
Around 6-8 weeks after conception, you may find yourself making a few extra trips to the bathroom.
Other Explanations: Urinary tract infection, diabetes, increasing liquid intake, or taking excessive diuretics.
Darkening of Areolas:
If you are pregnant, the skin around your nipples may get darker.
Other Explanations: Hormonal imbalance unrelated to pregnancy or may be a leftover effect from a previous pregnancy.
Food Cravings:
While you may not have a strong desire to eat pickles and ice cream, many women will feel cravings for certain foods when they are pregnant. This can last throughout your entire pregnancy.
Other Explanations: Poor diet, lack of a certain nutrient, stress, depression, or impending menstruation.