This is totally normal when going off the pill. The pill suppresses ovulation and when you go off of the pill, it takes a while sometimes for ovulation to start up again. This is because while on the pill your body relies on those hormones and doesnt bother to make its own. Once you stop taking the pill, it takes your body a while to go "Oops! I'm not getting hormones anymore! Better makes some!" No hormones being made means not only no ovulation, but also not enough build up in the uterus each month to be shed in the form of a period. Give it a bit longer. Your body will realize soon enough that it needs to make hormones again and then your period will return.