Personally I would start this cycle fresh and start temping now. Basically it is a wait and see game if your cycles are not regular yet. It is hard to "calculate" or predict ovulation when your cycles are not normal iykwim. Therefore observe your cervical mucus and take your temps. Record all your information and you may start to see a pattern. DTD when you see your mucus change to egg white or watery and then see if you get a temp rise over 3 consectutive days. By having a consistent temp rise you'll know that you have already ovulated.

Hope that helps.