Is my calf okay yet?!

The 15K trail run is under 1 month away. At this point I have not even hit the trails in the Vibrams. This calf strain has hurt my training routine! I am now reevaluating my plans to run the 15K in the Vibrams. I may bring my running shoes with me and change into them if I feel any problems.
I had to travel last week so my running was off. I tried to use the tread mills at the hotels with poor results. I ran the first night for about 1 mile and felt like my right calf was pulling (not the one that was hurt). I decided to take it easy and quit for that night. Two days later I tried it again. Maybe it is just me or the speed was off on the tread mill but a 10 minute mile felt like a 9 minute mile, 9 felt like 8, and 8 felt like 7. I started off at 10 minutes per mile, sped up to 9, after about 1 mile I sped up to 8. The last mile I tried a seven minute mile and it really beat me down. I suppose I have not run much in the last month but do you lose that much ability so quickly! I finished 3 miles with no calf pain. The next night I did another 3 miles again with no calf pain. My calf feels tight and tingly sometimes but no pain. I have been stretching and exercising both calves. Running on tread mills takes some getting used to. I ran all times in my Nikes.
I ran on Sunday on the road in my Nikes and made it 4 miles with no calf problems. I went relatively slowly and I am just trying to build up my mileage again. I need to get back to 8-10 miles on my longer runs.
I have added a new exercise to my routine. I bought a trampoline for my daughter and we get out there about every other day or so. Bouncing on that thing is a blast and seems to be a good work out. Due to the fact that I am 46 and probably break easier now than I did when I was in my teens I don’t get too wild. I have been trying some flips but with some apprehension. I hope bouncing like that doesn’t hurt my calf again. Meanwhile my daughter is doing flips and front hand springs.
I went for a run Tuesday (April 27th) with the Vibrams. I ran mostly in the grass with some excursions on the street. I felt great until about 2-3/4 miles then all of a sudden I felt like my left calf was going to tear again. I was maintaining an 8:30 minute mile so I was not going too fast, although I was heading up a slight hill. All of sudden it felt like a cramp was getting ready to kick in. I immediately stopped and walked back. There is no pain whatsoever right now. I am just not sure what is going on. I will give it another try on Thursday. I can’t hurt it now because I have the mud run coming up on Saturday. I don’t want to let my team down.

Have a great day!

Gary