Blood pregnancy test

So I haven't had my period and I'm late 19 days I took 2 home tests in the last 2 weeks and both negative and so I finally went to the doctor.  They did a urine test and it was negative i asked for a blood pregnancy test and the doctor didn't think it was necessary.  I want to make sure that I'm not or if I am.  Then they said they want to do a ultrasound Tuesday to make sure I don't have all these different kind of syndromes and what not...never heard of any of them and I can't remember what they were but she had a list of them.  Should I be scared or worried? And you think the doctor was a little out of line telling me that a blood test wasn't necessary?  I am a little worried and my period is always on time...opinions or advice anyone??