Answer (1 of 7): If you ovulate later than normal in your cycle then implantation could occur the day after your period is expected.
What is pregnancy spotting like? How can I tell the difference
How to know if you have implantation bleeding - Quora
Can implantation bleeding occur four days after you miss your
Is this implantation bleeding or menstrual period? - Quora
Does black period blood mean pregnant? - Quora
Is it possible to have implantation bleeding a day before a period
When does a woman have the highest chance of getting pregnant? Is
What are the common first signs of pregnancy? How can I tell if I
Can you find out you're pregnant before your period? - Quora
Could you get pregnant 2 weeks before your period? - Quora
Why am I spotting when I haven't gotten my period in more than 3
What's the difference between implantation bleeding and
Bleeding after Plan B: When it's normal and when it's an early
Can implantation bleeding occur after 3 days? - Quora