Confused and anxious

Hello ladues, I have my first appointment on tuesday, I have no idea how far along I am. I have had irregular periods my whole life, I just found out I was pregnant last monday April 6. So I immediately made a appointment. Do u think my obgyn will perform a ultrasound. Oh my last period was Jan 1, but I did take a test March 7 and it was negative. Thanks for your help.