Late period

Leah

My period is 4 days late, I haven’t been sexually active for 2-3 months now and I am never really late and if I am it’s only one day. I’ve had my period for around 3-4 years now and most times I cramp up really bad like 4-5 days before and get sick plus have heck of acne. That hasn’t happened? Did my period not happen this month?