Runner's opinion

So what is everyones opinion on incorporating a race into a long run ? It is my first race since Gwen was born . Part of me wants to run the race straight and see where I am at (it is an 8k) Marc and I are in our third week of training . It is a pretty intense training schedule. I ran about 50 miles last week. Breastmilk seems to be holding up. But trust me it is not fun to breastfeed , pump out, run out the door run 15 miles and come back and try and breastfeed again. Anyway I have to do 14 miles . What do you think ?