Negative IVF Blood Test: Early Pregnancy Possibility & Next Steps

Question
i am 34 years old, my last day of my menstral cycle was April 27.  On May 15 I had two embryo's implanted.  13 days later I had a blood test done which came out negatvie.  I have read if the test is done too early there is not enough hcg to give a positive test.  I have been taking progesterone shots and the nurse told me that is why my period has not happedned and it should happen in a couple of days.  Is there any way that I am pregnant that it was too early?

Answer
Usually, we do not like to take a preganncy test (either blood or urine) until 14-21 days after ovulation. If you had the imiplantation on May 15, I would think that a pregnancy test would not show a positive result until 14-21 days later, or May 29-June 5.  I would suggest that you repeat the test on June 5. If it is still negative, you are not pregnant.