No flutters/bubble feelings at 18 weeks

Hi mummies! I am 18 weeks pregnant and I have yet to feel much flutters or bubble-like feelings that was shared to me by my other mums. Some people told me that I could feel the baby’s heartbeat by putting my finger into my belly button but yet, I still couldn’t feel anything. Is it normal to not feel any movements yet at this stage? #firsttimemom #firstbaby #advicepls