Confused

So I got my period 5 days ahead of schedule, which is pretty odd for me. I had pretty intense cramping but not a normal amount of bleeding. It lasted for 3 days and has stopped. I had been feeling poorly the past 2 weeks with cramping and light headedness. My husband and I have been trying for 6 months. I took a pregnancy test on Sunday that said "not pregnant". I feel as though I should take another test but it could all be stress related... Advice would be wonderful!