Wacky cycles

Hi all, so my cycles have been kind off all over the place. Most months have averaged 33/34 days but I’ve had one down to 30 days and two over 46 days. My husband and I just started “trying” last month, but I just don’t even know when I ovulate so I don’t know when to start testing. My cm changes constantly but When my cycle is so off, it’s not consistent with telling. I have a toddler and a busy schedule so I’m afraid I couldn’t be on top of temping. I don’t want to buy ovulation tests or too many hpt’s either. This past month I spent easily $60 on hpt tests (including many of Walmart cheapies) since it was so late. I can’t do that every month until a positive comes. Any advice?