Period is 2 days late..!!

So I usually start my period the same day of every month. This month, I’m two days late. I’ve taken two digital pregnancy tests, but they’re the cheap kind. Both say, “not pregnant.” The only time my period has ever been late was when I was pregnant with my first. Could I be late because my cycle isn’t regulated from having my first? My last two periods were on the dot and then this one isn’t. Should I try a better brand of test? Wait a few days and see if it comes and if not take another test? I’m going crazy because I’m never late!!!