Will it be a goodbye?

so today I had a docs appointment where I was going to get and US, I was excited!! i will be 17 weeks on Saturday, when we start the US I ask the doc if he thinks he might be able to see the gender, he says maybe but this is his second time using the US machine in the clinic. when we see baby I swear I don't notice a heartbeat, he keeps checking and says that the US says on only 12 weeks. it can't be, I had my pregnancy test one day after I missed my period, he keeps looking around and says that it's really hard to measure the baby be used he is all wrapped up and not moving at all....I feel my heart slowly sinking...he decides to take two pics but doesn't give any to me becuase they honestly don't look like a baby. when I get up and pull my shirt down, he asks me if I haven't had any bleeding I say no, he then asks me if I still feel pregnant...I say, yes, I actually do...I leave. I thought it was going to be a happy moment but now I feel like the worst is going to happen...I had been very emotional this morning...I had been crying all morning for no reason and every reason (if you know what I mean) I have an US in the hospital tomorrow morning. I hope it was just a very big mistake and baby is okay