Can someone help me on this please

So I'm 15 weeks today I go too the doctor at 10am and yes I consider today Monday even if it is 12:30 at night too me once it says am it's morning dark,or not but anyways some of my friends think that it's weird that my baby hasn't moved they said that since it's my third baby I should be able too tell movements but I don't even feel it move I just always thought the baby moves like at 20 weeks or over so I'm just looking for some advice of how it actually works like can you feel the baby move this early