Conditions Stress Related To Nail Trimming

I experienced something with my piggies Saturday which I have not experienced before and just thought I would throw this out here. I don't trim my boys nails myself because to be honest, I am just too worried about hurting them. They tuck those little feet in faster than I can hang onto them so I opted to take them to the vet to have the vet techs cut their nails and they do a great job. They are in and out of there fairly fast and the last time they were glad to be home but this time totally different story. I got them home, into their cage they went and neither one of them came out of their cozies all day which was really odd behavior for them. I took them out cuddled with them for awhile and they were very quiet so I think they were absolutely stressed. One decided to finally eat much later that night and the other I ended up hand feeding as he would eat sitting on my knee. Veggies sat which never happens so it was all a new experience to me. Sunday morning same scenario (except they did eat their treats, not their veggies though) and yesterday afternoon they came around and are back to their normal little guinea pig ways. Not sure if anyone else has had this happen but you have any advice, I would love to hear it. Thanks a bunch and I apologize for blurbing so long.