Worried--lack of movement


I've been feeling flutters/little kicks since about 18 weeks, and I'm 21 weeks now. The movements have been sporadic, but I usually feel then daily when sitting. Today I have felt a couple of things but none that I am 100% confident are movements. Is that normal at this stage? Also, last night I had a dream about going in for an ultrasound due to lack of movement. Hopefully I'm just an anxious first time mommy. Wish my baby girl would give some reassuring kicks.