Whether it is normal to be 52 days pregnant without any reaction to pregnancy vomiting depends on the development of the embryo, if the fetus develops well, it is normal. However, if ultrasound is done and abnormal fetal development is found, it should be considered that the embryo has stopped developing. 52 days of pregnancy belongs to the early stage of pregnancy, some women will experience early pregnancy symptoms such as nausea, vomiting, chest swelling, frequent urination and so on during this time. If you do not experience any symptoms at this time, you need to go to the hospital for an ultrasound to see how the embryo is developing. If the embryo is well-developed and the embryo buds are already seen pulsating, it is not considered abnormal even if there are no such early pregnancy reactions, because every person has different physical conditions and tolerance to early pregnancy reactions. If ultrasound examination reveals that there is no bud pulsation or the gestational sac is shrinking in the follow-up examination, this situation should be highly suspected that the embryo stops developing. At this time, the hormone level in the body gradually decreases, so the early pregnancy reaction will disappear. This is an abnormal phenomenon, and the pregnancy needs to be terminated as soon as possible.