Should I be worried? Period only 2-3 days

Hey ladies, so long story short. I had my period last week but it only lasted 2 full days and spotting on the third. (you know how a period is the last day normally) Normally my periods are 4-6 days. I took a pregnancy test the 20th of December and it was negative. I read something somewhere that if you bleed during pregnancy it’s normally spotting but never enough to fill a pad up. The period that lasted 2-3 days filled pads up and was like my normal period. Cramping, bloating etc. Also December’s the first month that I truly started being sexually active. Like had sex when I got the chance. (About 6 times in the whole month before my period) so maybe I thought since I have started having sex that during sex it “moved” things around and that maybe caused my period to be only 2-3 days long. Have y’all had your period change the length since y’all have had sex or has it always stayed the same? Should I be worried? I plan on taking another pregnancy test soon but I doubt I’m pregnant. What do y’all think??