Nearly all of the major organs are formed during what period?

At this stage of its development around 10-12 weeks I think, all major body organs have formed inside the fetus. These organs would not be able to function if the fetus were outside of the uterus. Between 10 and 12 weeks, the fetus begins to make small random movements

All organs are formed in the fetus. About 12 weeks is when the fetus starts to make movement.

You can literally find this on google of each science career and search up what type of training you need and how many years in school