I wouldn’t jump to the conclusion that it’s the bottom bracket. While it’s easy to assume the bottom bracket, more often than not it’s either (1) your pedals, or (2) your seat. Seat is easy to rule out, just pedal around out of the saddle and if it still does it. If your riding clipless pedals, clean them good and put some chain lube on them, really get it in there and try it out. I swear most of the time its dirt/grit in the pedals or seat rails. Much easier/cheaper to problem check these than get all into the drive train. Good luck!