I'd rather sit on the sidewalk 15 - 30 min. & change 2 tubes or patch small punctures before walking 5 miles. I know changing tubes or patching small punctures out in the field stinks, but it's not as bad as walking 5 miles

also, maybe you just had a leak? do you carry a pump or CO2 so that you can limp home & do the changeover later? meaning pump, ride, pump, ride etc ...? sometimes it's an option

fwiw ~ someone once suggested using a cotton ball to slide around the inside of the tire to find the small perpetrator

good luck!

p.s. maybe a smooth tread tire would be less likely to pick up something that can puncture the tires