Metallic taste, gassy, nauseous- what is it?

I’ve been having a constant metallic taste in my mouth for the past several days and today I woke up super nauseous on and off all day long. I was worried I was pregnant so I took a test and it was negative. But my period isn’t due again until next month and I’m worried it was a false negative. Anyone have these symptoms?

I take hair skin and nails vitamins every day but I’ve been taking them for about a month now and I’m just now getting the metallic taste.