There are multiple causes for bleeding during pregnancy, but it doesn't have to be a cause for concern.
Although the risk of miscarriage is higher in the first 12 weeks of pregnancy, blood loss does not always mean gestational loss. Some of the reasons for small bleeds at the beginning of pregnancy are: hormonal changes, a genital infection or sexual intercourse.
If the bleeding is large or too frequent, then it can be worrisome and trigger an abortion alarm. In that situation, it will be advisable to consult with the doctor.
For more information, consult the following article: Is bleeding during pregnancy normal?