What exactly are Follicles?

[babylove717]

So here's the story, I have been off of birth control completely since August 2012. I had a normal period until about November it was a steady 4 days and 31 days between. I was able to track them no problem but since December they have been all out of wack! my period was 4 days late in December so we decided to take a trip to the doctors, not pregnant! THEN i did not get a period at all in January and instead got it February 6, again normal 4 days. However i was having a huge amount of discomfort in my lower abdomen where my ovaries are. So i made an appointment to get an ultra sound and i did. She said i had a lot of good looking follicles and that everything looked great. She said this summer we can do further testing to see why i have not yet gotten pregnant. But at this point we're okay with not getting pregnant yet i just want to know what my body is doing? Again my period is late this month..

Any thoughts? Any similar things happen to anyone?

Thanks for taking the time to read this lengthy case.
xoxobaby dust!