Fetal monitoring... feedback wanted please

Hi I’m 28 weeks this is my second time in a week span going to labor and delivery due to high BP for monitoring. Of course my BP is high at the doctor office. I get to L and D and it’s dropped drastically from 150/80 to 107/57. I know I get nervous going to any apt. As for them monitoring the baby, this has also happened twice where his own heart rate randomly drops from 140/150 to 70 and then they have my change position and he regained a rate of 150. That made me stay for another 2 hours for monitoring him. They said he probably grabbed his umbilical cord. I really don’t know what to think of this