Understanding Transvaginal Ultrasound & Early Pregnancy Concerns

Question
THANKS SIR FOR YOUR QUICK RESPONSE, THOUGH IM SCARED YOUR RESPONSE IS HELPFUL. SO IF MY HCG KEEPS DOUBLING, WHEN YOU SAY THERE IS A VIABLE PREGNANCY YOU MEAN THEY JUST MAY HAVE MISSED THE BABY? I HAVE READ THAT IT IS BEST TO HAVE AN ULTRASOUND WITH A FULL BLADDER. I HAD NO WATER MOST OF THAT DAY. IS IT POSSIBLE THAT'S WHY THE BABY WONT SHOW UP? THANKS AGAIN FOR YOUR RESPONSE.



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Followup To
Question -
I went to the emergency room since I saw a pink spot on my undies, this is my first pregnancy (I'm 21) so I worry. Anyway I had a transviginal ultrasound and they saw the gestational sac but nothing more. Im apparently 7 wks 3 days (the day I went to the hospital.) They gave me another ultrasound sent the results to a hospital in Dallas and they said there is no baby. Im scared, but I've read and read in my despair to find and answer. The first day of my last period was July 28. Please help me figure this one out. It cant be that there is no baby. I have all the symtoms, my clothes are not fitting, my breast are tender am I'm making this pregnancy up? That there is no baby? I have had no excessive bleeding and the HCG levels keep rising, still have morning sickness. PLEASE HELP! Can it be that there is no baby?
Answer -
If your last period started on July 26, you should now be 7 weeks 4 days pregnant (from the fist day of your  last period). By now, a sonogram should show a fetus and a fetal heartbeat. If there was only an empty gestational sac, it means that you either had a "blighted ovum" or a miscarriage. I would suggest that you take two blood tests for pregnancy (Beta HCG) 48 hours apart. If there is a doubling of the results in 48 hours, it indicates a viable pregnancy. If there is a halving of the results in 48 hours, it indicates a miscarriage.

Answer
If there continues to be doubling every 48 hours of HCG, that usually indicates a viable intrauterine pregnancy. HOwever, a sonogram should be able to identify a gestational sac, a fetus, and a fetal heartbeat after 6 weeks from the first day of your last period. If they only see an emty gestational sac and there isn't any increase in the HCG, it does not bode well.