Some people during pregnancy, morning sickness is common. Some said it is pure luck that some women doesn't get it.
As for me, I don't think this is luck. In fact, there is a strong link between morning sickness and the lack of vitmain B.
During my wife pregnancy, she took a lot of B-complex and thus, she did not experience any morning sickness. Her friends said she is lucky. You need a lot of hardwork to get luck and, she was hardworking enough to take the B-complex on a daily basis.