This might sound silly but can you tell if it's the in-breath or the out-breath (or both?) because apparently it can mean different things.
They can get bits stuck in their nose, in which case if it stops it shouldn't happen again. If it happens again try and get a video. Look for any unusual discharge from the nose or eyes, or coughing or sneezing. It won't be a 'cold'... guinea pigs don't get colds.
Dicky breathing can indicate a respiratory infection (urgent, but treatable) or possibly heart issues (which you can't correct, but can be medicated to improve things). Or sometimes something totally unexpected. I had a weird 'honky' noise from my little girl which seemed very loud but which lasted only a few mins at a time. After the 3rd time within about 10 days I took her to the vet. They couldn't hear anything at all in her lungs but I'd videoed it and they said it was very pronounced. But the next time she went in, the vet found large ovarian cysts and we wondered whether they were just giving her a bit of aggro sometimes. We discussed a spay but currently she's got no symptoms so she's on a small amount of painkiller twice a day and she's being monitored by eating, pooping and weight maintenance (as a general anaesthetic is a risk for them). We've not heard it since. Flora doesn't give anything away so we're just going day by day!