The doctors don't get concerned about the baby moving until the end of the 2nd/beginning of the 3rd trimester, then you should feel the baby daily.because your only 19 weeks and its your first pregnancy you prop wont feel he or she move regularly till around 22 -23 weeks!, its nothing to worry about some babies are very active and others are lazy all depends on your little one :)
I still freak out when I don't feel my baby. So I know exactly what to eat or drink to get him going! A dounut or s can of Pepsi does the trick! But baby gets tired easy so that day probably took a lot of energy so ur baby is probably pooped out! :) or moving when ur asleep! I wouldn't worry to much but try drinking something cold, or a dounut, wake em up a lil:) I'm 19weeks as well.ftm
Oh I also ate candy at the movies which I NEVER do.