So confused and stressed!

​I'm not entirely sure when I ovulated, my other app calculated that I ovulated Monday 19th, so that would make me 8DPO if I ovulated Monday right? I've taken a pregnancy test this morning, BFN! My cervix is high, and I have had a fair amount of CM today, I have felt tired and nauseated on and off all day today, and tonight I feel nauseated and light headed. Extremely tired after 9 hours sleep at night. AF due 3rd of next month. 
​Does the BFN I got today mean I'm out? And does all of this sound normal? What else do I have to look out for?  I'm getting frustrated!