Brown spotting?

Hi everyone. We are on our fifth month ttc, and I'm having a strange cycle. My period is about 1-2 days late (varies between 25/26 days). After BDing last night, I had some brown spotting and it continued a little bit this am, just a little when wiping but nothing else. I took a hpt yesterday (dollar tree) despite trying to avoid that because I'm tired of negatives. It too was negative. Am I out this month? Anyone experienced anything like this?