Missed my period 3 times in 8 months?

Rose

Right after I turned 25, I missed my period for the first time. It freaked me out because I have always been regular and have been off birth control since June of 2023. I missed my period in December 2023, but I wasn’t too concerned, because I was pretty stressed from final exams. I missed my next period in April 2024, again I had exams. It’s now July and I am 2 days late, but experiencing period symptoms as I usually do (whether it comes or not). I wouldn’t say I’m under a lot of stress. Some yes, but not nearly as much as during my first year starting school. Maybe, because I was on birth control then I didn’t notice how the stress was affecting my body. I am going to make an appointment with my gynecologist, but any ideas of what’s going on until then?