Pain and ectopic

Hello all,

I recently found out that I am 4 weeks pregnant. But I have some pain on my left. The doctor immediately did an ultrasound and said he did not see an embryo in my uterus. So he said it could be ectopic pregnancy. He also said it might be too early to see anything so ordered blood tests. Did anyone have pain one side and end up having/not having an ectopic pregnancy?

I am very worried.

Thanks for all your answers in advance!