When you take a pregnancy test it's best to wait the full time unless obviously you see something blatantly obvious before, because if it's early on it could be faint and take that time to show.
If you have been on bc for this long then I think chances are it's messing with your hormones and it's taking time to adjust. You have been putting hormones into yourself you wouldn't usually have - usually your body would be in control whereas a pill has been doing it for you for some time. My sister came off the pill for a while after being on it for quite a few years and her cycles were all messed up.
It isn't unusual and you will eventually see your cycle go back to how it should be, but it could take time. Everyone is different, for some their cycle will return to business as usual within a couple of weeks, for others it takes longer. There isn't an average to be honest because it will vary so much between women. I wouldn't be concerned at the moment. I think if you don't see your period in a couple of weeks and you don't see a positive test visit your doctor, but I suspect things are adjusting and isn't anything to worry about. The symptoms you are having are likely to be down to hormones adjusting and I would take this as a good sign your body is trying to get back to how things were before the pill, even though I know how frustrating this can be! It will get there though