Is it safe to say that I'm pregnant?

The last time I had sex was May 7th and my last period was mid April. I have skipped two periods both in May and June and have taken two positive pregnancy tests which were taken two weeks ago. I have also seen my doctor who has tested me and the test also came back positive. From May 7th until now is 8 weeks and I am considering abortion. Do I need an ultrasound to officially confirm pregnancy or is it safe to say I'm 8 weeks pregnant?