How can you tell your baby is still alive??

Mariko
Just wondering and I know this is a bit scary thought... 
I think I am the lucky one who doesn't get morning sickness. And I don't know if my tummy now has the baby bump, or just because I've been eating a lot... Bigger boobs don't mean that I am still pregnant. 
How can I tell the baby is still growing inside of me without going to see the doctor??