Period is late

Well I'm officially a day late. I've had my period back since my son was 10 months old, so for 4 months now. It's been between a 31-33 day cycle and I'm not passed the 33 days. I know it can be late but I'm a little worried because I had a streak of bright red blood about a week ago (implantation?). Got a negative hpt today, but going to test in the morning.