You're supposed to do one new food at the time so that if you run into an issue you have a clearer idea what food my be a problem.
Did the peanut jar get to you? Terrible tempting stuff.
Did you up your carbs as you added nuts as well?
Are you close to your period? Any other stressy things happening that may make you hold on to water right now?
Sorry for all the questions but there are many factors to consider before you jump to the conclusion that nuts indeed are an issue.