Delayed period or Missed?

How can I tell the difference between a delayed period because of later ovulation and a missed period all together due to pregnancy? I haven’t had sex but my period is now 3 days late and I’m off the pill so my ovulation isn’t the same day every month. I know stress can delay your period but I feel like I would’ve gotten my period by now. I’ve been feeling kind of crampy, tender breasts and bloated. Any advice would help as I’m pretty nervous.