A chemical pregnancy is used to describe a very early miscarriage. There can be many causes but with these cases, very early miscarriages don't result in embryos or fetuses with a heartbeat. The fertilized egg may not implant well into the lining or it may even graze the lining just enough to get a positive test. These miscarriages occur around 4-5 weeks or so. Some women may not know that they have occurred. It is noticed more because women can test 5-6 days early for pregnancy, get a positive result, but the egg doesn't take and they start their cycle on time or a few days late. It basically causes the chemical signs of pregnancy without an egg developing into a fetus.
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