If you're able to lay on your stomach, do so on a soft surface like a bed or couch. That helps me feel my daughter when she's being stubborn sometimes(: you could also be mistaking gas feelings for baby movement, I've been feeling my baby kick since I was 13 weeks.

thanks @lizzyamcmahan was getting worried

Anytime now you should feel a kick

some don't feel it til 23 weeks it won't be long

you should feel him already. or at lest I did at 18 week with my daughter.