Pregnant With Baby #4

I'm 19 Weeks Pregnant Today && I Haven't Felt Her Kick. By This Time With My Other Pregnancies, I've Already Felt Strong Kicks With Them. But For Some Reason I Haven't Felt This Baby Kick At All. I Do Feel From The Inside "Movements'' But When I Look Down At My Stomach 2 See If I Can Actually See Kicks, I Don't. I'm Worried. I Have My OB Appt Tomorrow Afternoon. I've Have Been Asking My OB Since My Last Visit If She Can Do An Ultrasound But She Won't. Last OB Appt I Heard Her Heartbeat && It Did Calm Me Down. But Now I Wanna See Her On The Ultrasound && Just See Her Move Just 2 Put Me At An Ease && Know She's Ok. Should I Keep On Insisting My OB 2 Do An Ultrasound Tomorrow?