Running a race that you don't feel prepared for

I am 5+ weeks out from a 10-mile race I signed up for pre-pregnancy and have only gone 5 miles (which weren't easy) max since finding out I was pregnant, due to fatigue and nausea. I'm 12 weeks along. Ideally I  would have stuck to my long training schedule to allow for mileage increases and recoveries, but my body told me otherwise and I tried to spend more time resting. I know I could walk some of it but there is a time limit to the race and I'm fearful of "pushing" myself too hard just to get it done. There is a 5k option I can drop down to but I was really hoping to get this accomplished. I was never an intense runner pre-pregnancy, usually 10-15 miles/week. Everything I read online with running advice for preggos seems to be from hardcore runners that could run 10 miles without blinking an eye, not an average/mediocre runner like me! Just looking for some advice. Also, my doctor is fine with me running overall as long as I'm hydrated and not pushing hard.