I'm really at a loss here, I need some advice...

So I'm on cycle day 50 my period was due November 27 and AF still hasn't shown up, my cycles have always been between 28 and 32 days no later not even when I got AF back after having my son this past March, and I've gotten a mixture of results for test I a got a couple positives and now negatives has this happened to anyone before? I have a doctors appointment scheduled for next Thursday and I'm gonna have them do bloodwork, I guess I'm just wondering has this happened to anyone and they still ended up pregnant?