So Confused

I track my period consistently and I'm late (one week and two days)...in the past, I've had irregular periods, but not for the most recentl two-three times. I'm not sure if I'm just stressing myself out which is causing it to be late or if I have actual reason for concern. I had protected sex before my last period (but still got it) and haven't since. Now does that mean I'm in the clear or not? I just feel like I'm never 100% sure. I've been feeling breast tenderness and cramps in my lower abdominal area for at least a week and a half to two weeks. I'm just trying to get opinions!! Please and thank you.