I also have a longer cycle and for me it's because my body doesn't produce progesterone as quickly/readily as most people. So it takes longer for my progesterone level to rise high enough to trigger a period. Due to this I've been able to get pregnant twice but unfortunately both ended in miscarriage. We didn't know at the time but now believe (after seeing a few doctors) that the pregnancies ended because my body didn't produce enough progesterone quickly enough to support a pregnancy. During the first trimester your progesterone level needs to rise substantially each day so if your body is already struggling to keep up, it may not maintain a pregnancy for very long. Prior to being pregnant everyone would say "it's normal" to have a longer cycle. That's true, as in it isn't uncommon, but make sure you work with your doctor to know what's at play. Luckily if it is a low progesterone issue you can get a progesterone suppository to supplement what your body is making and hopefully maintain the pregnancy.
I don't think there is anything wrong with a longer cycle. Mine is always longer than "normal". I read that some women have 40 day cycles. If you are worried, you should call you Dr- you should be able to just call and ask.