I took a HPT last monday, came up postive, called my doc he ordered blood work,which confirmed my pregnancy.?

The doctory ordered me to come in one week later, tomorrow to have more blood drawn to make sure numbers go up. I had no instructions to start taking prenatal vitamins or anything. Is this normal? This preg is a suprise...my hubby and I have been trying for years to conceive, This is the second fetlilty doc we have went to. They said that I did not ovulate this cycle and and were gonna introduce a triggger shot next cycle...well how i turned up pregnat I have no idea, we did it naturally without IUI...We are both overjoyed but very nervous!! Thanks for the help!!