I am heavily pregnant and have been using perineal massage to prepare for birth (this helps reduce tearing). I usually massage once per day but am increasing to 3x per day next week as I will be on maternity leave and have more time during the day. I use a perineal massage oil in a glass jar (so no squeezing tube, just pouring a little on my finger). Is it permissible to do perineal massage on Shabbat? Thank you.