Hello,
Even after doing exercises, your heart rate should not exceed 140 bpm.
If you're using electronic devices to measure your heart rate, I would suggest you do not rely on them.
Although pulse oximeter is a reliable tool, there maybe some technical limitations to it.
Next Steps
I suggest, you go see a doctor as soon as possible.
Nothing beats a doctor checking your pulses and heart rate manually.
Get your Blood Pressure monitored
Health Tips
Also , avoid heavy exercise for the time being.
Avoid stressors .