I'f period due today and you started bleeding then it's most likely to be your period starting off slow.

Honestly looks like implantation spotting! I had the same for 2 days on the 16th and 17th this month, now I'm 5 days late. I'm never late nor due I ever have spotting or discharge like that. So I'm hopeful for you and me! Good luck, please update when you know!!