How to know...

Hey guys! I've been posting a lot recently, I find this site to be very helpful. I am 16w + 5d ~ I still get nauseous at the smell of the fridge in the morning, and I have an increased appetite. Plus my bump is defintely there! I think I am feeling little tiny flutters of movement from time to time. And yet I still have this lingering concern in the back of my head that "what if something has gone wrong?" It's just this fear I have. We heard the heart beat again at 15w and 5d right before we got on a plane to LA. Now I will be without my doctor for a little longer  than a month. Can anyone offer advice as to how to relieve that slight worry I have? For example, would there be a sure sign that something is wrong (i.e. Cramping or bleeding)? And if that type of obvious thing doesn't happen, then that probably means that everything is still smooth sailing, right? Thanks in advance! Xx