Am I ovulating?

So I️ recently stopped taking birth control on the 28th. My doctor told me that it is possible I️ could release an egg. My period was supposed to come on the 30th but didn’t come until the 1st. It wasn’t like a normal period it only lasted about 3-4 days. I️ am now cramping but not bleeding and having a backache. Could that have been implantation bleeding? I’m not supposed to ovulate until the 14th but my cervix is super high, soft and open. Any ideas?