If you have determined when you want your calves, then the bull is in the pasture with the cows as required (283-285 days prior to the beginning of your calving season). If she cycles, he'll take care of things & if her reproductive tract has healed enough, she will settle (many factors come into play here). On the other hand, if you are in your defined breeding window (time wise to meet your calving season) & doing AI, you should allow at least 45 days for her to heal before going thru the time, trouble, effort, & cost of semen associated with breeding. That is a minimum, I did a couple at 40 days last yr in an attempt of move them up & neither caught. I saw 60 days on another post (certainly should have a healthy repro track given even fair nutrition), but that amount of waiting begins to push the timetable to stay within a 1 yr window (if things don't go well on the first breeding attempt or you miss catching her in heat, or if she was late to begin with then you will not be able to move her up much).
Then again I had a cow that rebred via the bull (one of those mistakes or unplanned pregnancies) at ~30 days post calving.