Non stress test question


So I'm 36 weeks pregnant and get non stress tests done weekly. My last test the alarm beeped a couple of times saying high heart rate for my baby. The doctor checks the chart at the end every time and the nurse came back saying everything looks good. Just wondering if this is normal? I didn't get to see the doctor afterwards to ask. I am doing another one tomorrow so if it does it again I'll ask the doctor after.