Level 1: What does it mean to be pregnant? Pregnancy biochemistry refers to the situation where the pregnancy cannot proceed normally due to chromosomal abnormalities or abnormal embryonic development after the fertilized egg implants. This condition usually occurs in early pregnancy and is also called early miscarriage. Level 2: What are the symptoms of chemical pregnancy? 1. Relief of early pregnancy reactions: Symptoms such as nausea, vomiting, breast swelling and pain in early pregnancy will gradually reduce or disappear. 2. Vaginal bleeding: A small amount of bright red or brown discharge appears in the vagina, even accompanied by abdominal pain. 3. Pregnancy test paper test results weaken or disappear: due to abnormal development of the biochemical pregnancy embryo, resulting in