I too had Hyperemisis and then was diagnosed with Placenta Previa Major at 20w scan. I felt like I had no time to enjoy my pregancy as I was either sick or worrying about bleeding out.
I had my diagnosis and they advised that as it was completely covering the OS I would need scans at 24/28/32/36 weeks. These were for placenta placement and growth scans as chances were baby's growth would be hindered. They also told me I would definitely bleed as the position was very risky and that my placenta would not move at all. Also told I would most likely need a blood transfusion at the time of my section as I would likely bleed a huge amount.
My first consultant said nothing about pelvic rest, although I had already googled and put myself on pelvic rest. My second however said to make sure I wasn't doing anything pelvis wise as the risk was too great.
Each scan showed the placenta still in its place and baby on smaller side although growing on their percentile line so not too much of a concern.
Each time I went to the toilet I was expecting blood. My stress levels were through the roof as I was just on high alert all the time. I was signed off from work because of all this from wk 29.
My section was booked for 38wk with the expectation that a bleed would bring it forward.
HOWEVER...I made it to the section date with no bleed at all. I lost just a litre of blood and no transfusion was required. My baby was on the smaller side at 6lb 2oz but is perfect and didn't need any attention at birth.
I spent my whole pregnancy worrying. I wish I could have relaxed more. The doctors have to prepare you for worst case scenario but my goodness I wish I could turn back time and just be calm in the knowledge that if I did bleed it would be okay as they know why I was bleeding and they would deal with it safely for me and baby.
I truly feel for you. Our pregnancies sound identical. Hyperemesis and Previa are soul destroying at what is meant to be an exciting time.