Hi AJP,
I'm not too sure how much help this will be because i am sort of in the same boat as u but thought i would reply. I also discovered that i had swollen up a little downstairs around the time that i think i was ovulating but i am not too sure as i am not exactly tracking my cycle this time round, however if i remember, the swelling lasted around a day or two and i was really aroused during that time!! I did only notice it this cycle as i was tracking my CM too. Funny the things we notice when we actually look!
I hope this helps a little bit