Long runs for 3 days

Just a tad over a month to go to the race and I'm thinking it's not quite enough. I did a 16 then 18 and a 13 miles In a row. Running on dead legs for these next two weeks I hope will be enough to get it for the 100k. I think did pretty well by the end. I have 1 rest day then a hard 18 to 20 miler before Saterday which I hope to get a marathon in bofore I have to go to work. Yes you read it correctly before work.
All 3 days on the runs I am fighting against time. the 16 and the 18 were not to bad though the legs were still strong and would have kept going but ran out of light with no moon. Though the 13 put sort of a challange to it with running 4 of it in a pasture. If you ever want a work out or run that will kick you around try that. You will feel it the next day for sure. Of is not looking good for the weekend runs prediction RAIN!!!