Is it normal to keep getting a minor tear in the same place (bottom of vagina-perinium location)? it produces spotting of blood after sex even with lube

Not normal: Vaginal tears are not a "normal" event during intercourse. Most likely you tore in this location and haven't ever completely healed. This area seems to be prone to stretching and is a hard location to completely heal. I've seen these persist for months. You need to get an exam to make sure there is no infection. Vaginal rest and topical estrogen also sometimes help. Best wishes!