My audio does match video taken in iMovie

I have been using the "capture" function on iMovie to make videos for just over a month now and I have never had a problem but the other day when I went to watch my video the audio did not synch properly with the video. Which doesn't make sense cause I did not edit it, and it was taken on my computer (macbook pro I bought in July or August) with the webcam through iMovie? Is something moving too slowly, do I have too many movies on iMovie? It would just be such a hassle, or near impossible to try and detach the audio to make it match properly with the video because it does need to be edited a good bit.

Any help would be greatly appreciated!!