doctors appointment

I when to the doctors for a pregnancy test they told me it might be too early to tell if I was pregnant or not because I was supposed too start on the 17th of July so they say I have too take prenatal vitamins and take another test next week on the 28th of July and see if its positive but I scheduled another appointment for testing on August 4th which is 2 weeks from now. if I am pregnant that would make me 6 weeks and 3 days pregnant. they say it's a possibility that I am pregnant because I have bleeding last week.