O-day confusion; when did I ovulate?

• a positive OPK,
• a temp drop which I assume translates to an increase in estrogen levels and
• quite some EWCM during CD18-19 to indicate that I was ovulating around then.

But my temps rose only by CD22. Also, Ovagraph lit up CD 19 as my peak day. What does that mean?

1. What is the difference between peak day and O-day? 
2. Did I ovulate on CD19 or CD21?
3. If I ovulated on CD21, does it mean that there's something wrong with my cycle as there was no LH surge before CD21(OPK tests were negative)?

Thank you for any information I can get on this confusing chart!

-Love, Yellow
Married since Feb, 2017
TTC #1, currently on cycle #5