Hello,, if not undergone scan already get it done as early as possible. First trimester scan is called dating scan (approximate date of delivery). Early scan gives you better approximation about date. And scan also helps to see where the baby is growing (inside or outside uterus (ectopic)) /about twins, to check fetal cardiac activity. Also helps to follow up pcod. Next scan will be 16-20weeks as anomaly scan, to see baby is growing normal or baby has any defect. Third scan will be towards term.