Could I still be pregnant?

Stephanie

Hubby and I have been TTC baby #2 for the last 4 months. On Friday, I was supposed to start my period. First thing when I woke up and wiped it was brown so I knew that was period coming. Now, 2 days later, it has never picked up flow, haven't even needed to wear a panty liner. I tested this morning but it was negative. Could I have just ovulated later so HTC wouldn't show up yet for it to be a positive? I'm just confused. My periods are like clockwork so the fact that it hasn't started yet is weird. What does everyone think?