Why is my period late?

I’m a few days late for my period and I’ve spent all morning googling things in order to feed my pregnancy paranoia.

Anyway, recently I switched from having to wake up at 8:30am to 3:30am (only getting 4–6 hours of sleep lately). I’m an amateur bodybuilder that participates in vigorous exercise 6 days a week for a total of 12 hours (my body fat % is still in a normal range, though). I smoke and consume approximately 900mg or so of caffeine a day. However, I have had unprotected sex this month using the pullout method and he did not ejaculate inside of me.

You would think that my lifestyle would make my body unfit to conceive, but is there a possibility? Or would it be best to blame my lifestyle choices and brutal schedule change for the late period?

I’m only a few days late but my body is usually like clockwork. I’m having symptoms such as intense constipation, swollen breasts, and moodiness, but giving that those are symptoms of both PMS and pregnancy, I can’t really differentiate.