Tracking your cycle

How are you tracking your cycle post hysterectomy? I have been on birth control for 20+ years. I know when my cycle should be happening based on that - but I know that without the pill my cycle won't be the perfect 26 days apart that it was prior. I haven't naturally ovulated since I was a teenager lol I know I don't really need to worry about it, but since I'm 41 (42 in a few weeks) I'd like to be able to keep track so I know where I'm at with menopause someday. I'm only 12 weeks post op - so it would have been hard for me to notice any changes up until now. I'm finally starting to feel semi normal now. Soooo, any advice would be helpful.