Can a fetus be seen by two weeks in a ct scan hypothetically speaking?

No: At 2 weeks of pregnancy (2 weeks gestation), ovulation is taking place. Nothing is visible on any kind of scan. Pregnancies are counted from the first day of the last menstrual period (or the presumed first day of the last menstrual period based on a 28-day cycle if the woman has irregular periods or doesn't know when her first day was). That means ovulation and conception happen at 2-2.5 weeks.