Overactive baby

Ki
Hey ladies-
Just looking for some support for anyone who has maybe gone through this...
I went in for my weekly checkup today, I'm 39 weeks on Thursday. I've been super sick and I mentioned that although I'm getting my kick counts in that the baby's pattern of movement has changed and it has been taking longer to reach 10. I was hooked up to a fetal monitor and she found that he was TOO active. His heart rate was jumping around from 130-175. He couldn't regulate.
I was sent to L&D. I'm measuring a week and a half behind now (a week last week) but his heart rate leveled out. My fluid was measured and I'm 10cm.
I go back in two days for another growth scan as they are concerned he is too small. He was 5 1/2 at my 36 week scan.
I haven't gained either. Has anyone had anything similar occur and still given birth to a perfectly healthy baby? I'm so worried right now. Even feeling him move now just freaks me out where it used to make me
so happy!!