First time mom ?

Ok so for the past week or 2 baby has been moving like crazy every day esp in the evenings but this week it hasnt moved around hardly at all. Is this normal.?.?.?.? I have a fetal Doppler and have been checking once a day on me little one and its heart rate is consistent. Just curious if this is normal or if I should be concerned, I go to the dr again on Wednesday and I'll be 24 weeks then. Any suggestions or words of advice or comfort?