Question about bloodwork and hormone levels?

I have been ttc for a few months now. I know that I am pregnant just by reading my body signs (leukhorrea) headaches, sore bbs, frequent urination, loss of appetite, backache etc... but I cannot seem to get a positive HPT. My Dr has scheduled me for bloodtest (before I was pregnant) as I told him that we have been trying and not been successful as yet. The test he scheduled me for is to test my progesterone levels. 1. My question is if I am pregnant as I suspect will he be able to pick this up in my progesterone levels if he does not test neccesarily for pregnancy? 2. Would he be able to pick it up through a pelvic exam? 3. Do you think that the frequent urination over the last five days accompanied with drinking lots of water could have diluted the preg hormone in my urine? thank you so much any reply/experience is welcomed! I have been tested for diabetes and UTI and I am all clear