Mid cycle bleeding *tmi* *no pics*

After sex I usually wear a panty liner for a few hours because of the sperm getting out and today after an hour I went to the toilette and the panty liner was light red. Very light red because it obviously mixed with the other body liquids ☺️ but I am worried why that happened. I don't think it was very much blood. I am cd10 today and I had some ovulation spotting before but not this much and never this early. Anyone ever had that?