Hey VeryV, I'm no expert in charting but I highly recommend it, it's one of the best ways to tell if you are ovulating and when in your cycle you do. It can be a little tedious as it involves buying a BBT thermometer (this is a more sensitive thermometer that measures your Basel temp - your resting temp first thing when you wake up) and taking your temp every morning when you wakeup. I have a 28 day cycle and the ovulation charts say I should be ovulating around day 14, well this is best case scenario i.e. the perfect cycle... and we are all so different. So after charting for the last 3 months I found that I actually ovulate around day 16/17/20 so if we were BDing at 14 we might miss ovulation if it's on day 20. It just makes your chances better plus it gives you a great picture of how YOUR cycle works not the virtual one the ovulation charts tell you. The only thing is that it can't forewarn you when you will be ovulating (only once you have) but that's where the OPK tests come in.
You should try Fertility Friend, it's a great site, all the info you need - here are my recent charts: https://www.fertilityfriend.com/home/2ee9ed I really feel knowledge is power.
Anyway don't be discouraged, we know all too well that we are not all like some woman who come off BCP and next thing you know - BFP! Hang in there, this might just be your body adjusting. Maybe test again in a few days?