When to test

So my husband and I are ttc and my period is due in 2 days and my boobs are SO SORE . They’re never this sore and my stomach has been acting weird like it won’t let me eat as much lately . Like usually I’ll eat a full meal but lately I barely eat a few bites and I feel sick to my stomach . I just have a feeling i might be pregnant . When is too early to test? I want to test now but i think it’ll be best to wait until the day my period is supposed to show .