Period length short

So I got my period 3 days ago and it was very heavy super red with lots and lots of cramps, bloating and back pain. Now I’m on my 3rd day and it’s very light it’s red light red. Is that bad? Is it normal? I read it can be sign of pregnancy but I took a test and it was negative, i used protection too. My period usually last 4 days 5 days max. Since my last period before this one I started working Night Shift, could it possibly be that? I’m not super worried but it is making me freak out a little.

It’s not light pink it’s still red but light. If that’s makes any sense? TYIA