Extremely odd period?

Hi! I wanted to ask this in case there’s something wrong. I noticed that my period was a bit off when it started yesterday, I didn’t get cramps as strong as I usually do, but Id taken a pain killer so I thought it might have been that.

I woke up today and I felt so bad, I was sweating and I was nauseous and on the second day I’m usually fine. I realised something was wrong when I got to the bathroom and my pad was bearly stained. I usually have a very strong flow so idk what is happening.

Any thoughts are appreciated!