help!

So my husband and I are TTC. I started my period today, or so I thought, and I only bled a little bit of brown blood and then it stopped. I keep track really closely using a diva cup so this isn't normal for me. My first day is usually extremely heavy. I also have endometriosis. Am I getting my hopes up or should I take a test? I have had a painful one sided cramp for about two weeks now.