Missed Periods, Pregnant, Slow Fetal Growth, Late Conception. Prescribed Susten, Buscopan. Complications?

Hi, I had My period on 19th February and when I did a Pregnancy test after a missed period on 19th march, it showd negetive result and I reperformed that test on 30th March which gave me a negative result again. However, when I took the test after missing my second period on 19th March, it gave me positive (2 lines clearly). There was a Similar result the next day too. Wehn i went to the Doctor, she did a scan via My Vagina and told me that I had to be 9 Weeks... However, the fetal growth shows only 4-5 Weeks. The following is the Result of the Viability Scan: 1) Single Intra uterine gestational Sac seen corresponding to 4weeks 5 days 2) Fetal Pole - Not Visualized yet 3) yolk Sac - Seen Impression: Single Intrauterine gestation, too early to confirm viability. She said, it cud be either a late conception or the growth of the fetus is too slow. So suggested the medication of : 1) Susten 200MG 2) Buscopan if there are cramps. Please Suggest if I am pregnant in a healthy way and if there would be any complications with both the medication and the analysis. Thank you.