15 dpo,BFN, how long do you wait to test again/get bloods?

[impatienttp]

Im 15 dpo, had really bad cramping yesterday but now it is nowhere to be found. I tested today in the middle of the day( because I absolutely could not wait!) and BFN. So, does anyone have any suggestions on how long I should wait to test again and if still BFN how late should you be before you have blood work done? And also you should know that I am always 29 or 30 cycle. Never more or less and I am now on day 32? Help please!LOL

 

[omgamandaa]

I heard that it can* take up to 21dpo to get a pos on a test. A friend of mine just found out she was preg and she was BFN up until 20dpo.