The earliest you can see the gestational sac by ultrasound is 42 days after menopause, and the fetal heartbeat and fetal bud can be seen by ultrasound around 50 days after menopause, which is for women with regular menstrual cycles, with cycles around 28-30 days. If the cycle is very unstable, it may be difficult to estimate the time when the ultrasound can see the gestational sac or the fetal heartbeat or fetal bud. Therefore, two weeks of pregnancy is the first time to confirm the pregnancy by taking a pregnancy test or coming to the hospital to have a blood test for HCG. If pregnancy is confirmed, the timing of the ultrasound will be inferred from the HCG results. If you plan to prepare for pregnancy, it is best to start taking folic acid tablets in the first trimester to prevent fetal neural tube abnormalities.