It is probably OK. The heartbeat is usually always present by six weeks even though it isn't generally detectable at five weeks. So your scan was done at a borderline time. Sometimes babies are actually younger than the dates indicate and so there isn't cause for concern just yet. If no heartbeat was detected in a subsequent scan and if your hCG levels started to fall, that would indicate a problem.
Yes the heartbeat doesn't show in week 5, possibly week 6 sometimes week 7, so dont worry what you saw was right for week 5.
You did not indicate what week you were at in your question. I am at six weeks one day today, and went to my doctor today for an ultrasound. I had one twin with a fetal pole and a heartbeat that was about four times the size of the other one, which had the gestational and yolk sac but no detectable heartbeat. My doc said that there is a possibility that the smaller one will not be viable (that it may have arrested), but that a followup ultrasound in two weeks is necessary to see if there is growth. The ultrasound tech said that she has seen fraternal twins implant at different times, thus resulting in different size sacs and different rates of growth. Assuming you are not far along, I don't think the size itself or lack of a heartbeat is definitive of having lost one of them, and they will probably be able to tell at a repeat U/S. You can also look up the concept of a vanishing twin - it is apparently a common phenomenon. In most instances, it is not harmful to the remaining twin when it occurs early on.
Listening for the fetal heartbeat is routine during a pregnancy appointment. Usually if a medical professional does not hear the heartbeat they will conduct an abdominal ultrasound to access the health of the unborn baby. It is unlikely that a doctor would not investigate further if they are unable to hear a heartbeat especially 6 weeks or more into the pregnancy. Less than 6 weeks a doctor may not be concerned yet about not hearing the fetal heartbeat and simply wait until the next prenatal visit to listen for it again.
There are many characteristics found in a fetal pig. Fetal pigs generally have all of the characteristics of an adult pig.
hair found on fetal pig is very thin and light-colored. it is found all over the pig's body.
Fetal pigs are found in a structure called a uterine horn. It is the point where the uterus and the uterine tubes meet.
Gestational diabetes is only found in pregnant women. However, general diabetes is not due to pregnancy. Only women are able to get gestational diabetes. http://www.healthscout.com/ency/68/203/main.html
I found out i was pregnant with my twins at 3 weeks. I got a positive pregnancy test at 2 weeks due to higher levels of HCG in my urine and then began bleeding so went to the ER and they done an ultrasound. You could see the gestational sacs, but not the fetal poles yet.
The trachea, heart, lungs, bronchial tubes, thyroid gland, and the larynx are found in the cavity of a fetal pig.
Fetal pigs are not as developed as an adult.
There is a very good reason there is no food found in a fetal pig's stomach. The fetal pig was never born.
Meconium
Brainstem.