Freaking out!!

Hey ladies, I went in for my first ultrasound and based off my last period I should of been 7 weeks 5 days.. my periods are irregular so I figured I wasn’t that far along. When she did the scan we couldn’t really see anything but a gestational sac. It was measuring at 4 weeks 3 days. there was a more sac and a fetal pole but I couldn’t really see. I wanted to know if anybody else has been through this! I go back for another ultrasound in 3 weeks but I know these next 3 weeks are going to go sooo slow. HELP me feel a little better :(