Confused HGC

nallsl

I had a blood test and urine test to confirm my pregnancy yesterday. My doctor wants me to go back tomorrow to do another blood test to check the HGC levels again. I think it's to see if the levels are increasing which means things are going as expected? 

Also, since I only had 1 cycle back in March, we are uncertain about the conception date. My doctor said I was "a couple of weeks" according to the blood test. If that is correct, then what would my approximate conception date be? I'm curious as to what my due date will potentially be. 

 I know that no one will have an exact answer, but some suggestions or guesses will be nice. Thank you!