I need some advice!

Here's what's going on. My period is a few days late and today I thought I was going to get it. Early this morning I had some lower back pain and felt very nauseous (kind of felt like this all week). A few hours ago I went to the bathroom and noticed some blood, both in the toilet (TMI SORRY) and some when I wiped. But it was very faint and light!! Usually when I get my period the first day is pretty heavy.