Talk to Gynecologist on Baby Movements

Hello Dr. I m currently 29 weeks 4 days pregnant .. i went for ctg yesterday and the ctg was reactive .. tonight my baby moved vigorously for about a min and then stopped i m worried is the sudden vigorous movement ia worrisome ?? After that no vigorous movement occur only kicks and rolls i feel.. i want to know for how long ctg is valid and how much movements should be felt at this stage of pregnancy because it freaks me out if i dnt feel the baby move for sometime