Serena Williams has revealed that she was particularly surprised to discover she was pregnant because she believed she had a period the week before finding out.
In an interview with InStyle the tennis superstar – who found out she was seven weeks along while competing in the 2016 Australian Open – says she only took a test to “shut up [her] friend” who was suspicious.
“I literally had a cycle just before. So I was surprised when I saw the result and even more surprised when the doctor said I was seven weeks along,” the 36-year-old said.
While experts have clarified that what Serena experienced was not actually menstruation, light bleeding during early pregnancy happens to around a quarter of mums-to-be.
“The vast majority of spotting is harmless,” says Maternal-Fetal Medicine Specialis Alyssa Stephenson-Famytold Parents, and common culprits include the implantation of the egg in the lining of the uterus, sexual intercourse, an infection or the side effect of an internal exam.
However it is still important to speak to a doctor to ensure that you and your baby are healthy.
Bleeding in the later trimesters of pregnancy is less common and can be the sign of a serious problem like placenta previa (separation of the placenta) or placental abruption (when the placenta covers the cervix). It is essential you speak to a medical professional if this happens to you.
This article originally appeared on Women’s Health