Brown on suspected period helpp ????

So I’ve been ttc,

This month (like every previous months)

I was waiting to see if my period came today, as today was the day of my suspected period,

But I am left with this dark/light brown discharge, I was shocked as normally I wake up on my suspected period day to go for a wee and my period comes with it.

So I thought maybe it’s left over blood leaving the body and my period will unfortunately be here in a minute, so I put a pad incase and go back to sleep (it was like 2/3 in the morning). I then I go the toilet again when I wake and there is no sign of blood on my pad, so I go toilet and it’s still brown coming out.

Is it just left over blood, and my period will look very soon ?