Exactly where is the pain/soreness/tweak? Were you experimenting with a high or low seat position?
Sometimes it can caused by a lack of stretching catching up with you.
I know how it feels to go nuts about missing a ride, especially during nice weather.
Last week I tweaked my
knee stepping onto a trailer, carrying something that wasn't all that heavy, and the next day I was a mess (mentally). It didn't hurt until I got on my bike later that day, then I totally 'sh@t' myself. I kept saying to myself: "just turn around, just turn around and go home; surely you can miss one day, you psycho" -- but I kept going and did about 20 miles. Luckily, no harm was done. I iced it that night, and it was back to 100% after about 3 or 4 days, but all throught that time I kept riding.
(.....hmmmmm, I've gone a bit off track again)