Every time I ask I always get told I'm 4 weeks pregnant. Today is August 19th and I had sex the 2nd, that was the same day I ovulated and was fertile the next day.. I was supposed to start my period 4 days ago but I've missed it. How far along am I ?"

Every time you ask... how often do you ask? How many times has this happened?

How far along are you... well, considering you're only 4 days late, it's kind of hard to judge that at this point. You don't even know for sure you're pregnant yet... or are you 4 weeks now because you asked?

To be honest, your question is somewhat confusing.

Who said you are pregnant? Four days late is not abnormal.

I meant every time I calculate

I meant every time I calculate
At 14 days late, you can test with the first urine of the morning.

The first sign of pregnancy is a missed period. 4 days late is NOT yet a missed period. So you don't even know for sure if you are pregnant yet, let alone how far along. As noted you need to wait another 10 days then take a pregnancy test according to the instructions.

Calculating conception dates is an inexact science. The only way to accurately pinpoint conception is if you only had sex ONCE since your last period. If you get a positive test in about 10 days then you make an appointment with your OB/Gyn. He can give you an idea of how far along you are.

Unless, there is an issue of paternity, it is not important to know exactly how far along you are as your gestation period can vary by a few weeks.

I agree, I doubt you even know you are pregnant, that has to wait at least 10 more days, to 2 week, just to test.

Number of weeks pregnant is often figured off date of last period, not an exact conception date.

Also if you had sex prior to this, it can be from that.

Also, to be blunt, I doubt you know for sure when you ovulate since online charts are estimates for many people, but then many people also ovulate at other times.
So unless you were testing for ovulation with medical tests, no you do not even know that.