A pregnancy scan can detect a gestational sac by transvaginal ultrasound as early as four to five weeks after your last menstrual period; a fetal heartbeat is usually seen from about six weeks. Abdominal scans are generally reliable from six to seven weeks. Exact timing depends on dating and hormone levels; if too early to see fetal structures, clinicians often repeat the scan after one to two weeks.

A pregnancy can be detected by ultrasound as early as 4–5 weeks’ gestation with a transvaginal scan, when a gestational sac may be visible. A yolk sac and fetal pole usually appear around 5–6 weeks, and a fetal heartbeat is commonly seen by 6–7 weeks (sometimes earlier with high-resolution transvaginal ultrasound). Abdominal scans often show these findings about one to two weeks later.

Yes — ultrasound can detect early pregnancy, but timing depends on method and hCG levels. Transvaginal scans may show a gestational sac by about 4–5 weeks, a yolk sac around 5–6 weeks, and a fetal pole with cardiac activity by 6–7 weeks. Transabdominal scans detect pregnancy later. Very early pregnancies may be missed; repeat scanning or serial hCG testing is often recommended.

A transvaginal ultrasound is the preferred scan in early pregnancy because it provides the clearest images of the uterus and embryo from about 5–6 weeks. It assesses pregnancy location (intrauterine vs ectopic), confirms viability by detecting a fetal heartbeat, and helps date the pregnancy. A transabdominal scan may be used later or alongside transvaginal imaging for comfort or later gestation.

Not usually. “2‑week pregnancy” is ambiguous: two weeks after conception (about 4 weeks by LMP) might show a gestational sac on transvaginal ultrasound around 4–5 weeks, but the embryo and heartbeat are usually seen at 5.5–7 weeks. If you mean two weeks from the last menstrual period (ovulation), nothing would be visible. A repeat scan at 6–7 weeks is common.

Yes. A transvaginal ultrasound can often detect twins as early as 6–8 weeks by visualizing two gestational sacs or embryos and separate heartbeats. Determining chorionicity and amnionicity is most reliable by 10–14 weeks. Occasionally a "vanishing twin" makes an early twin pregnancy appear as a singleton later. Accuracy improves as pregnancy progresses.