I Was Supposed To Start My Period 4 Days Ago

I was supposed to start my period 4 days ago and I thought everything was fine
because I started to get light discharge that was a brownish red color that
usually accompanies my period. I'm on the pill which is why I knew It was
supposed to start on Wednesday. But I feel like I haven't had a real period
yet it's just been light discharge and I'm worried that I might be pregnant.
Is that possible? I started the pill I think 2 or 3 months ago and I usually
take it on time but there have been a couple times when I forgot and took it
the next morning or I took it an hour or two late. I've had sex twice without
a condom since I started the birth control.