Hi. This is just possible at 4 weeks 5 days gestationand that too transabdominal. One may not see cardiac activity and foetal pole at this gestation.
It is possible that you have conceived late and that is why gestation period is less. I will advise you to start treatment from your dr. in the form of micronised progesterones vaginally and other what she advises to be appropriate. If no spotting or bleeding then wait for 2 weeks and get a TVS done .Thanks.

Hello
Thanks for writing to us with your health concern.
Normally, cardiac activity appears on ultrasound scan by 6 weeks, when the scan is done vaginally.
Abdominal scans are not as reliable as transvaginal scans in dating a pregnancy.
Also, what was the date of your last menstrual period ?
If you have a history of delayed cycles, or irregular cycles, then you can wait and watch for another week for a repeat scan, which might show heartbeat.
Meanwhile, take rest.
Avoid stress and intercourse, and take the medications as prescribed.
Please ensure that the repeat scan that is done after a week should be done transvaginally.
If you have cramping / spotting / pain or expulsion of clots at any time, go the ER immediately, and do not wait for a week.
All the best.
Please feel free to discuss further.

Hi,
Thanks for writing to us.
It is normal that at 4-5 weeks of pregnancy you can only see gestational sac and you can not see yolk sac.
You should go for repeat ultrasonography after 2 weeks to see the foetal pole and heart beat.
Good luck.
Regards
Dr. Richa