Morning sickness typically begins around 4 to 6 weeks after conception, which is about 6 to 8 weeks from the first day of the last menstrual period.
Timing Details
Pregnancy weeks are counted from the last menstrual period, so symptoms often start 2 to 4 weeks after a missed period or positive test. Some women notice nausea as early as 2 weeks post-conception (around week 4), but week 6 is most common.
Peak and Duration
Nausea peaks between weeks 8 and 10 for many, then eases by week 14, though it can persist longer in up to 10-20% of cases.
Variability Factors
Not everyone experiences it; about 70-80% do, influenced by hormones like hCG. Twins or sensitivity to smells/foods can intensify onset.