This is baby #3. At 12 weeks, dr. couldn't find heratbeat or feel fundus? Why? I thought it all came sooner?

My doctor didn't check me for either at my 4 month check. Im ok so far. Im sure you are too. At my first check he checked the size of my uterus and didn't try for the heartbeat then either. I get my scan this Wed and he said we may as well wait for that. My baby is a active little fart and I really was more annoyed than worried.