I always know when I ovalute - I don't even need to test because I get the side pain.

Some months are definitely worse than others - sometimes I even get sore skin and can't stand being touched but usually Nurofern or something helps alot with that. I don't get headaches but I definitely have had the pain. I can't tell you why some months are worse than others - there doesn't seem to be a rythm to it - it just is.