Cycle after emergency contraceptive pill

I took an emergency contraception pill (first time ever using one) February 22 last month, my boyfriend and I didn't use anything and u hadn't realized in the moment that it was perfect time of the month for me to get pregnant. Anyway took the pill and within 4-5 days I began spotting and what was similar to my period. That lasted about 3-4 days. That wasn't considered my next period was it? From my understanding I should expect my regular period around my usual time. Well it hasn't come yet, and I'm about 6 days late if I should've been expecting it to come as usual.... Is that typical of emergency contraceptives? My boobs are also really sore (usual my sign my period is coming) but they have stayed sore for a week. Should I get a pregnancy test or am I being paranoid?