Tad bit concerned

My DH and I just started TTC this last month. I normally have a 26 day cycle that lasts 4 days with a medium flow and heavy cramps. This month i startex a day early and spotted for 2 days... had a light flow on day 3 and have now spotted for another 2 days. I had no cramps or a headache till the ladt 2 spotting days. I have never had this before. Ive tested and all came back negative. Any suggestions?