I've heard that a normal menstrol cycle is 27days. mine is 36days. is that bad? can that cause infirtility?

There is no "normal": At your age, you periods are probably totally normal, as long as they are consistent and otherwise normal. The exact timing is not relevant. If you have concerns, check w/your gyn.

Range: Cycles can range from 23 to 35 days and still be considered normal. It doesn't mean that you are infertile, or subfertile to go out 36 days, it just means that you ovulate later, perhaps as late as d22 of your cycle.