My body is confusing me

This month I had no pms symptoms, no sore boobs or cramps or anything. My period came a day late , lasted for a day and a half.. Again light period no cramping at all, it almost felt like I had no period... Then today (cycle day 3) after having no bleeding all day , after sex I had a small amount of bright red blood, then nothing .
We are TTC... Could I be preg or just a very weird period?