I was suppose to get my period on the 28th of August and its been two days and I haven't got my period. How long should I waite to see if I am pregnant?;)

Typically a week to two weeks... I wouldn't even really consider two days "late"... and Im regular..

I took an hpt 1 day after my missed period and it came up positive. I suspected pregnancy so I couldn't wait any longer. But if you wait a week or two you are more likely to get accurate results. If you take one now and are pregnant you might get a negative because you don't have enough hcg built up in your body.
If you are like me and can't wait take one now, if it is negative take one again in a week or two if you don't get your period.