hospital visits?

Noemi • Proud FTM to my beautiful baby girl Melanie Jazmin
I'm a first time mom I'm 24 weeks pregnant and the hospital I go to for checkups schedules for a visit every month or every 4 weeks, is this normal or should they be scheduling me more often? I feel like there's a lot of time in between but maybe it's just me? Also after your 20 week ultrasound do you get any other ultrasound? Like I see people posting 30-35 week ultrasound or even in 4D, is that something they do at a certain number of weeks? Thanks for any answers I'm just curious.