NEED OPINIONS

I've been having headaches/migraines for the past 6 days... I never get headaches. Unless I go without coffee or caffeine which I haven't. I'm suppose to start in 6-8 days... I've been cramping a lot and very tired! And kind of constipated and never had a problem before. Also really bad lower back pain. I'm 26 and married and we've been not trying but not protecting either so if it happens it happens :) but I was wondering if I could be feeling symptoms early and what signs you got early? Because I'm obviously not going to take a test unless I'm late.