soooo late

Ok so I'd really love it if you ladies could give me some feedback. I'm 6 days late now. The opk was pos on cd 13/14. I've only had brown spotting on and off for the last week (when my period should've been) I've done hpts and all neg and even a blood test which was only a hcg level of 2.... I'm going back to the doctors next week for hormone testing and an ultrasound if my period doesn't come on. Just wondering if anyone has any experience with this? Am I not ovulating? Could I actually be pregnant? Trying. Or to stress but I'm getting concerned something's not right 😔