The only way to know for sure is your 1st ultrasound, cuz I convinced later after my period then the typical woman so calculating from my last period was wrong for me..id just make an appointment
I'm 6 weeks right now and I took a pregnancy test last week, the 88 cents one from wal mart and it turned positive as soon as i put the pee on it
I think you should go by the last menstrual and make sure that your hcg levels are rising normally, take a 99 cents store pregnancy test it should come out positive right away if you're 6 weeks