Some amount of apprehension and tension in the period before the wedding in many instances is quite normal, especially in the kind of circumstances that you report. It is difficult to judge from your report if the issues are significant enough for you to consider any change. You may consider talking with a friend or family member who you can trust and who you believe would understand your apprehensions, or even your fiance!
It does not seem a very helpful thing, for your own wellbeing and health, that you have not shared your concerns with anyone. Do consider this option and then decide whether you need to go for a professional consultation or not. The menstrual problem you have mentioned is very possibly due to the psychological tension, and should get okay with time.