Dizzy at 25 weeks w/ twins?

Wondering if anyone has experienced this.

I'm 25 weeks with twins and woke in the middle of the night to let my dogs out. I was a little off balanced and dizzy and assumed it was due to being tired.

Well I get up for today and still feel the same. Just a little dizzy. Nothing too severe but it's there.

I drink tons of water and have always had completely normal blood pressure.

This is my first time experiencing it and it made me a little nervous since its later in my pregnancy.

Thanks!