According to your LNMP, today the gestational age
is 4 Weeks 6 Days. If you do an Endo-Vaginal sonography
, now, an experienced sonologist will be able to pick up a well defined sac, but fetal echo and cardiac activity cannot be detected, assuming you conceived on 14th day of your menstrual cycle.
I hope all those medication that you mention, you are taking under medical advise and supervision. If your obstetrician feels that is the best line of treatment, then you have to follow the advise of your obstetrician.
Worry is not a solution to every thing. Certain things can be answered only after a particular period of time and there is no point in worrying in the mean time. Hope for the best and think positively.
Wish you all the Best.