Very confused and scared?

I was supposed to(according to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a>) get my period on the 25th of this month, but it is now the 28th and nothing....my nipples have been insanely sore for the past week, which normally happens right before i start, but it hasn’t come yet! I had a period dec2-6 AND dec 27-jan. 1st? I’ve never had two in one month and they were both super heavy like my periods normally are? Anyone have anything that can help me calm down? I have had protected sex and that’s it but I’m still so scared.