Worried she is bored with me

I have been with my fiance for 5 years now, we are getting married in sept. As of late our sex life is almost non-existent. We maybe have sex once every two weeks or so maybe longer. Now she turns me on all the time and she knows it, she will tease me and do things but when I go to start things she always tells me no. After we moved in together the sex life was wonderful easily nightly but it slowed down to the point it is at now. After 2 years living together we were having sex maybe once every 3 days but I didnt mind that. But this last year it feels like she is bored with me, I use to be able to get her in the mood no matter what, Even now I am trying new things that are frankly out of my comfort zone that she has always wanted me to do to still be turned down. I have been in past relationships before and this was how it always happened, but it always happened sooner and faster. Now my fiance and me when we do have sex its great, we both climax (I know she does because she makes me stop because its to much for her) and after I normally finish ether by her giving me a bj or back inside her (she normally has another orgasm if im back inside her) What Im getting at is I really dont understand why she doesnt want to do anything anymore. I have talked to her about this, told her that I was worried about her being bored with me, and that she isnt attracted to me or I dont turn her on anymore. and she keeps telling me that isnt the case, she just isnt in the mood. Which to me is the case, if she isnt in the mood anymore then Im not turning her on....I really dont know what to do, I constantly hear that once you get married sex leaves the relationship quickly and if we are already having problems in that area am I looking at a sexless marriage? No matter what Im going to marry her I guess what I am asking for advice about is what should I do about us not having sex, should I stop trying? Should I keep trying?

You must not feel disheartened. Confidence is so important for a woman. Has anything happened that might have affected her confidence? Maybe stress at work, weight gain, just feeling like she's not the young sexy person you fell in love with. I have no doubt from your post that she hasn't changed in your eyes - you obviously still find her as beautiful and sexy as always, maybe even more so! But to a woman the smallest change can make you feel different. I'm not saying your fiancée has any serous issues, maybe all she needs is a little reassurance that she is still the person you fell in love with and fancy like mad! The worst thing would be to make her feel worse implying she's frigid or something. Trust me, a little reassurance goes a long way! Saying "I love it when you..." is so much better than "why do you never..." Even if you don't know why, every woman just wants to hear "You're beautiful". Hope you understand, sounds like you've got something good there.