Hi Rylansmum
Low BP is common in early pregnancy but a little unusual at 34 weeks. However your BP is not scary low just a little low. Some people naturally have a low BP. Take your time when standing or sitting up from lying down. This should help to prevent you from passing out and should help to reduce the dizziness.
The Ketones in your urine are caused by either Vomiting, not eating enough or Lack of fluid