You can't count on regular movements yet, mama! Try not to worry too much yet! That's why they don't have you start kick counts until 28 weeks! You should feel some movement most days around now, but unless there's a total lack of movement for a few days, try not to stress out. :-)
If you havent felt your baby move to much dont stress out, ur baby still pretty little at 20 weeks and soem women dont feel any movement untill 16-18 weeks try maybe drinking some ice water, that usasly will get the baby going but if its been over 24 hour since u felt any movement i would call the doc.
Don't worry you aren't alone, this is my first pregnancy, I'm 19 weeks along and when I don't feel her move all the time I start worrying then just try and breathe and remember that she can't be active enough for me to feel all the time just yet. We should probably just enjoy this time to sleep for when the painful kicks come and then when they finally arrive =)