Period weirdness

So I was over 20 days late for my period(never happens, even though I’m young), and then I got my period but it was so weird. I had no PMS symptoms, and no symptoms during my period either except for blood, and it only lasted(with a very weak flow) for 4 days.

Usually it lasted a week with bad cramping, severe mood swings, insane cravings, the occasional migraine, and lots more.

I’m on a heavy course of antibiotics because of a severe health issue I had recently, could that cause the irregularity?