should I test?

I keep reading that you should test a week after your missed period. Is that a week after the last day of what your missed period should have been or a week after your period should have started? I'm nine days late and my period has been like clockwork the past few months. Is tomorrow (10 days late) too early to test? My symptoms have been cramping in back and side and vagina on Tuesday and Wednesday which made me think my period was coming but no blood yet. Also itchy boobs, feeling moody, sneezing a lot (like 5 times a day and I've never been a sneezer before) and extreme fatigue (also I've been sleeping like a rock even more than normal) I know you aren't doctors but what do you think?