How do you track how far along you are with late ovulation??

I have an appointment at the end of the month, but so curious to how far long I could be… my last period was mid April to mid May (extremely long, a week of spotting before and after) took a test mid June and it was negative. Took a test beginning of July and it was super positive. I’m assuming my ovulation was late, but I don’t know how far I would be since I know they normally go off of the first day of your last period. But there can’t have been a lot of growth of the embryo I wouldn’t think to put me that far along if I didn’t implant until much later in my cycle than normal…