Tips Please!

So I stopped taking birth control in October and my period was regular until March, (been trying since October) well I hadn't had a period from March until July (no positive test) and I just recently started. I called my doctor back in April and she said that its normal since I'm off my birth control, that it'll eventually get regular again...maybe. My question is is since my period isn't regular anymore what's a good way to know the best time to bd since we're still trying? Since I had a period this month is it a possibility that I'll ovulate this month? Can I still ovulate each month even if I don't have a period each month?