Pregnancy Blood Tests: Accuracy, Early Detection & Abnormal Symptoms

Question
Are blood pregnancy tests 100% accurate? Is is possible to take a blood test too early to detect HCG?

My doctor gave me Provera which brought down my period on April 9 (this period lasted 17 days). I haven't had a period since. I took a blood test which came out negative. I have been having cramps, nausea, fatigue, and vomiting for 3 1/2 weeks. I have also had a pink discharge after urination and after intercourse a few times. Could I still be pregnancy even though it was negative?  

Answer
Hello Pamela. The blood test is accurate 8-10 days after sex. I don't think you are pregnant- but you may have something else going on that needs to be checked out. Just in case by some miracle you ARE pregnant- be sure you are taking a daily folic acid supplement of 1-2mg. All the best- Cheri.