Anyone?

So my obgyn had me get a blood test to confirm the pregnancy and the progesterone levels. Everything was great but they don't want to see me until I'm 10 weeks ? Why do they wait so long ? I understand the risk of miscarriage decreases over time but that seems like a really long time to wait... Expecially wen this is my first pregnancy I have a ton of questions? I see girls getting sonograms at 4 weeks ? I'm 5 weeks and I haven't gotten one?