Im probably lucky in that I have irregular periods but I do ovulate (had hormones checked and all is fine) Its hard when you are trying to conceive as your cycles may be much longer..but I found ovulation tests a lifesaver..the clearblue one was spot on (the one that shows a smiley face when you ovulate) I couldn't tell with other brands as there was always two lines on the stick anyway..as pp mentioned there are drugs like clomid that make you ovulate if you aren't already..good luck ttc!!
I have irregular cycles too and have been trying for 6 years. They usually want you to try for a year after you stop birth control because even when having regular cycles it can take a while so I would talk to your partner and get off birth control track your cycles also take the ovulation test throughout your cycle to see if you might be ovulating .. I was off birth control so when I went to see a specialist 4 years ago they tested me to make sure the irregular periods weren't something more serious...Turns out I just wasn't ovulating so they put me on clomid, a fertility drug to help me ovulate, once on that I was regular...still took a long time before I got pregnant but now I'm 16+4 weeks. So do not give up, I might happen quick or take a while. Good luck!
I would suggest stopping your BC and charting your cycle for at least 6 months before seeing a doctor. You will be more familiar and more educated on your body and your cycles. I suggest a book called Taking Control of Your Fertility. Some people just have odd cycles.
There are lots of women with this problem, a reproductive endocrinologist/ fertility specialist can help! But you can't get pregnant while you're on birth control of course so you need to see a doctor to get started.