Waking up dizzy & nauseous

Good morning everyone, I am 17 weeks pregnant this is my second pregnancy, early this morning around 2 am I woke up really nauseous although I couldn't get anything out I was also very very dizzy, so dizzy it was hard for me to walk to the bathroom then back to the room, I elevated my legs, I drank water, but still can't seem to understand why this is happening, has anything like this happened to anyone on here? This is my second time experiencing something like this although the last time I was actually up at work so last night took me way off guard