Nausea n slight dizziness during my first day of delayed period, is there anything need to worry about?

Normal but: It is kind of normal unless the flow was super heavy than usual. Either way the best way to over come it drink a lot of water and sport drinks like Garorade around that time , if persisted ask your physician to order a blood count to make sure you are not anemic, check you BP and your HR. In many positions laying down, sitting up , and standing and see if there is any variation .goid luck